Block-Boss Level: A Freelancer's Guide to Mastering Gutenberg & Full-Site Editing

Ralph Sanchez

Web Developer

WordPress Developer

Web Designer

Content Creator

Frontend Engineer

WordPress

GitHub

Computer Software

Block-Boss Level: A Freelancer's Guide to Mastering Gutenberg & Full-Site Editing

What Are Gutenberg and Full-Site Editing (FSE)?

From Classic Editor to Block Editor: A Brief History

FSE Explained: Block Themes, Templates, and Global Styles

Becoming a Power User of the Block Editor

Advanced Block Features You Might Be Missing

Creating and Using Block Patterns

The Anatomy of a Custom Block

Setting Up Your Development Environment

Understanding block.json

The edit and save Components in React

Styling Your Blocks: From Inline to Global

Best Practices for Block-Specific CSS

Leveraging theme.json for Consistent Design

Unlocking Client Value with FSE

Building Flexible and Empowering Client Sites

Introduction to Migrating a Classic Theme

Conclusion

References

Block-Boss Level: A Freelancer's Guide to Mastering Gutenberg & Full-Site Editing

The WordPress landscape has shifted dramatically. If you're still clinging to the Classic Editor, you're missing out on the biggest evolution in WordPress history. Gutenberg and Full-Site Editing (FSE) aren't just new features—they're the foundation of modern WordPress development. For freelancers, this shift represents both a challenge and an incredible opportunity. Clients want flexible, modern websites they can actually manage themselves. The old days of hardcoded PHP templates are fading fast. Today's WordPress developers need to think Beyond PHP and embrace the block-based future.

Here's the reality: businesses looking to hire WordPress freelancers increasingly expect block editor expertise. They want developers who can create custom solutions that feel native to WordPress. The good news? Once you master these tools, you'll unlock a whole new tier of projects. Just like the skills needed to become a Headless Hero, block development opens doors to premium client work. This guide will take you from block beginner to FSE expert, covering everything from basic concepts to advanced custom block creation.

What Are Gutenberg and Full-Site Editing (FSE)?

Let's start with the basics. Gutenberg isn't just an editor—it's a complete reimagining of how WordPress handles content. Full-Site Editing takes this concept and extends it to every corner of your website. Understanding this foundation is crucial before diving into development.

From Classic Editor to Block Editor: A Brief History

Remember the old WordPress editor? That simple text box served us well for years. You'd write content, maybe add some HTML, and call it a day. But as websites became more complex, this approach showed its limits. Page builders filled the gap, but they came with their own problems—bloated code, vendor lock-in, and inconsistent experiences.

WordPress needed a native solution. Enter Gutenberg in 2018. Named after the printing press inventor, it promised to revolutionize content creation. The reaction was... mixed. Many developers resisted the change. Some still do. But here's what they're missing: blocks aren't just about pretty interfaces. They're about giving users real control while maintaining clean, semantic markup.

The shift happened for good reasons. Users wanted more flexibility without touching code. Developers wanted reusable components. Site owners wanted consistency across their content. Blocks solve all these problems. They turn content creation into a visual, intuitive process while keeping the underlying structure clean and portable.

FSE Explained: Block Themes, Templates, and Global Styles

Full-Site Editing arrived in WordPress 5.9, and it changed everything. Before FSE, themes controlled site structure through PHP templates. Changing a header meant editing code. Adjusting colors required CSS knowledge. FSE flips this model completely.

Block themes are the cornerstone of FSE. Unlike traditional themes, they're built entirely with blocks. Your header? It's a collection of blocks. Your footer? More blocks. Even your 404 page is just blocks arranged in a specific way. This means everything becomes editable through the same familiar interface.

Templates in FSE work differently too. Instead of PHP files, you get HTML files containing block markup. Want to change how all your blog posts look? Edit the single post template in the Site Editor. Need different headers for different pages? Create template variations. It's visual editing applied to your entire site structure.

Global Styles tie everything together. Through a simple interface, you control colors, typography, spacing, and more across your entire site. Change your brand color in one place, and it updates everywhere. Adjust your heading sizes globally without touching CSS. The theme.json file powers this system, defining your design tokens in a structured way.

The magic happens when these pieces work together. A block theme provides the structure. Templates define layouts for different content types. Global Styles ensure consistency. Users get unprecedented control without breaking things. Developers get a standardized system that's actually enjoyable to work with.

Becoming a Power User of the Block Editor

Before writing a single line of code, master the editor itself. Too many developers jump straight into custom blocks without understanding the powerful features already available. This knowledge will make you faster, more efficient, and better at training clients.

Advanced Block Features You Might Be Missing

The block editor hides some incredible features in plain sight. Let's uncover the tools that separate power users from everyone else.

Block locking changes the game for client sites. You can lock blocks completely, preventing deletion or movement. Or use content-only locking, letting clients edit text while preserving layout. This single feature solves the age-old problem of clients breaking their designs. Apply it to headers, footers, or any crucial layout elements.

Group variations offer layout superpowers. The Row and Stack variations turn the basic Group block into a flexible container system. Row creates horizontal layouts with gap control. Stack handles vertical spacing perfectly. Combine them for complex layouts without custom CSS. Add a background color or padding to a Group, and you've got a custom section.

Typography controls go way beyond font size. Line height, letter spacing, text decoration, and text transform are all available. Drop caps add visual interest to blog posts. The Font Library lets you add custom fonts without plugins. These tools give you magazine-quality typography control right in the editor.

Aspect ratio settings for media blocks ensure perfect proportions. Set your images to 16:9, 4:3, or custom ratios. Videos respect these settings too. Combined with the Cover block's focal point picker, you get precise control over how media displays across different screen sizes.

Don't overlook the List View panel. It shows your entire page structure in a collapsible tree. Drag blocks between deeply nested containers. Select hard-to-click elements. Jump to any block instantly. For complex layouts, List View becomes indispensable.

Creating and Using Block Patterns

Block Patterns are pre-built block combinations ready to insert anywhere. Think of them as templates for sections rather than entire pages. WordPress includes dozens by default, but creating custom patterns unlocks real productivity gains.

Creating patterns is surprisingly simple. Build your block combination in the editor—maybe a testimonial section with image, quote, and attribution blocks. Select all the blocks, click the three dots menu, and choose "Create pattern." Give it a name and category. Now it's available in the Pattern inserter forever.

Smart pattern creation involves thinking reusable. A "Team Member" pattern might include an image, heading, paragraph, and social links. A "Pricing Table" could combine columns, headings, lists, and buttons. Build these once, use them everywhere. Your clients will love having professional layouts at their fingertips.

Pattern categories keep things organized. Create custom categories for different use cases: "Hero Sections," "Call-to-Actions," "Team Layouts." This organization helps clients find the right pattern quickly. You can even lock patterns after insertion, maintaining design integrity while allowing content edits.

Synced patterns (formerly reusable blocks) add another dimension. Changes to a synced pattern update everywhere it's used. Perfect for elements like calls-to-action that appear multiple times but need consistent messaging. Just remember to document which patterns are synced—clients need to understand the implications of editing them.

The Anatomy of a Custom Block

Now we're getting to the good stuff. Custom blocks let you create exactly what your clients need. No compromises, no workarounds—just purpose-built functionality that integrates seamlessly with WordPress.

Setting Up Your Development Environment

Modern block development requires a JavaScript toolchain. Don't panic—WordPress makes this easier than you might think. You'll need Node.js and npm installed on your machine. These tools handle dependencies and build processes automatically.

The official @wordpress/create-block package scaffolds everything you need. Open your terminal, navigate to your plugins directory, and run npx @wordpress/create-block my-custom-block. This single command creates a complete block plugin with modern build tools configured.

Your new plugin includes a development server. Run npm start in the plugin directory, and it watches for changes, rebuilding automatically. No manual compilation, no configuration headaches. You write code, save, and see changes instantly in WordPress.

The generated structure follows WordPress best practices. You get separate directories for editor and frontend assets. Build scripts handle optimization and compatibility. Even internationalization is set up from the start. This scaffolding eliminates the boring setup work, letting you focus on actual block functionality.

VS Code with the right extensions makes development smoother. Install ESLint and Prettier for code quality. Add WordPress-specific snippets for faster coding. The React Developer Tools browser extension helps debug your blocks. These tools aren't required, but they'll make your life much easier.

Understanding block.json

The block.json file is your block's blueprint. It tells WordPress everything about your block—its name, attributes, scripts, and more. Understanding this file is crucial for building maintainable blocks.

Start with metadata. The name property needs a namespace to avoid conflicts: "name": "my-plugin/my-block". Add a title users will see and a description explaining its purpose. The category determines where your block appears in the inserter. Choose from existing categories or create custom ones.

Attributes define your block's data structure. Each attribute has a type (string, number, boolean, object, array) and optional default value. You might define a heading attribute of type string and a backgroundColor attribute for styling. These attributes store the block's configuration and content.

The supports property enables editor features. Add "color": true for color controls. Include "spacing": { "padding": true } for spacing options. These supports integrate your block with WordPress's design tools, giving users familiar controls without extra development.

Script and style properties point to your asset files. The editorScript loads JavaScript for the editor interface. The script file runs on the frontend. Similarly, editorStyle and style handle CSS for editor and frontend respectively. The build process generates these files automatically.

The `edit` and `save` Components in React

Every block needs two core components: edit and save. These React components define how your block behaves in the editor and what HTML it produces.

The edit component creates your block's editor interface. It receives props including attributes and functions to update them. Here's where you build the UI users interact with. Use WordPress's built-in components like TextControl, ColorPicker, or MediaUpload. These components maintain consistency with core blocks.

function Edit({ attributes, setAttributes }) {
    return (
        <div>
            <TextControl
                label="Heading"
                value={attributes.heading}
                onChange={(heading) => setAttributes({ heading })}
            />
        </div>
    );
}

The save component generates the final HTML. It receives attributes but can't use hooks or state—it must be a pure function. This HTML gets stored in the database and rendered on the frontend. Keep it semantic and clean. WordPress handles the wrapper element, so focus on the inner content.

The beauty lies in the separation. The edit component can be as complex as needed, with rich interactions and real-time previews. The save component stays simple, producing clean HTML. This architecture ensures your blocks remain portable and future-proof.

Remember that blocks can have no save function at all. These "dynamic blocks" render via PHP on the server. Perfect for content that changes frequently or requires server-side logic. You register a render_callback in PHP that generates the output using current data.

Styling Your Blocks: From Inline to Global

Great functionality means nothing without great design. Styling blocks properly ensures they look perfect in the editor and on the frontend while playing nicely with theme styles.

Best Practices for Block-Specific CSS

Block styles need careful consideration. You want enough specificity to style your block without interfering with others. WordPress provides the perfect setup—if you follow the conventions.

Each block gets a unique class name based on its name: .wp-block-my-plugin-my-block. Always scope your styles to this class. It prevents conflicts and makes your CSS predictable. The build process automatically handles this scoping when you use the standard setup.

Write separate stylesheets for editor and frontend when needed. Editor styles might need adjustments to work within the editing interface. Maybe you need to override some editor defaults or ensure your block looks correct at different zoom levels. The editor.scss file handles these cases.

Responsive design requires special attention in blocks. Users might preview at different device sizes in the editor. Use relative units and fluid layouts. CSS Grid and Flexbox work beautifully for block layouts. Avoid fixed widths that break on mobile devices.

Consider style variations for flexibility. Register multiple styles for a single block, letting users choose different appearances. A "Card" block might have "Default," "Outlined," and "Elevated" styles. Users pick their preference from the block toolbar. This approach provides options without complexity.

Leveraging theme.json for Consistent Design

The theme.json file revolutionizes WordPress theming. It centralizes design decisions, making consistency automatic. Your blocks can tap into this system for cohesive styling.

Define your color palette in theme.json. Your blocks automatically inherit these colors in their color pickers. Users choose from a curated set that matches the site design. No more random hex codes breaking visual harmony. The same applies to gradients, giving you consistent background options.

Typography presets work the same way. Define font sizes with names like "small," "medium," and "large." Your blocks reference these presets instead of hard-coded values. When the theme updates its typography scale, your blocks adapt automatically. It's responsive design at the system level.

Spacing scales bring consistency to margins and padding. Define a spacing scale from small to large. Block spacing controls use these values. A "medium" spacing means the same thing everywhere. This consistency makes designs feel professional and intentional.

Custom properties (CSS variables) from theme.json are available globally. Reference them in your block styles for dynamic theming. When users customize their site through Global Styles, your blocks update automatically. It's like having a design system built into WordPress.

Unlocking Client Value with FSE

Technical skills mean nothing if they don't translate to client value. FSE isn't just about new tools—it's about delivering better outcomes for the people who hire you.

Building Flexible and Empowering Client Sites

The old WordPress way created a frustrating dynamic. Clients needed developers for tiny changes. Want to update footer text? Call the developer. Need a new header layout? That's billable hours. FSE changes this relationship fundamentally.

Start with smart template design. Create templates that give clients control over what matters while protecting what doesn't. A header template might lock the overall structure but leave the navigation menu and logo editable. Clients update their menu without breaking the layout. They swap logos without touching code.

Template parts are your secret weapon. Break templates into reusable sections—headers, footers, sidebars. Clients can swap different versions without rebuilding entire templates. Maybe they want a different footer for landing pages. Create a variation, and they can switch between them visually.

Pattern libraries become client empowerment tools. Build a comprehensive set of patterns for every common need. Hero sections, feature lists, testimonials, pricing tables—cover the basics. Document each pattern with clear names and descriptions. Suddenly, clients can build professional pages without design skills.

Training becomes easier with FSE. The interface is consistent everywhere. Once clients understand blocks, they can edit anything. No more explaining different interfaces for content, widgets, and menus. Record a single training video covering block basics, and clients can figure out the rest.

Set boundaries with smart locking strategies. Lock structural elements completely. Use content-only locking for sections where layout matters but content changes. Leave marketing areas fully unlocked for maximum flexibility. This graduated approach prevents disasters while maximizing client autonomy.

Introduction to Migrating a Classic Theme

Many freelancers face a common challenge: clients with classic themes wanting modern features. Migration might seem daunting, but it's a massive opportunity. You're not just updating code—you're transforming how clients interact with their sites.

Start with an audit. What does the current theme do? Which templates exist? What custom functionality lives in functions.php? Document everything before touching code. This inventory guides your migration strategy and prevents missing features.

Begin with hybrid approaches. You don't need to migrate everything at once. Start by enabling the block editor for content. Add block patterns that match existing designs. Let clients experience the benefits before committing to full migration. This gradual approach reduces risk and builds confidence.

Convert templates strategically. Start with simple templates like the 404 page or search results. These have less complexity and fewer dependencies. Move to archives and single posts next. Save the homepage and complex templates for last. Each successful conversion builds momentum.

Preserve custom functionality thoughtfully. That custom post type might work better as a block pattern. The widget area could become a template part. Some PHP functions might need to become dynamic blocks. Think about what serves the client best, not just one-to-one conversions.

Testing is crucial during migration. Check every template at different screen sizes. Verify that plugins still work correctly. Test with different amounts of content. FSE handles some things differently than classic themes. Catching issues early prevents client frustration.

The payoff justifies the effort. Clients gain incredible flexibility. Maintenance becomes easier. Future updates are simpler. You position yourself as a forward-thinking developer who delivers modern solutions. That reputation leads to better projects and higher rates.

Conclusion

Mastering Gutenberg and Full-Site Editing isn't just about learning new tools—it's about embracing WordPress's future. The block editor and FSE represent a fundamental shift in how we build websites. For freelancers, this shift creates incredible opportunities.

The technical skills we've covered—from understanding block architecture to creating custom blocks—form your foundation. But the real value comes from applying these skills strategically. Build flexible systems that empower clients. Create reusable solutions that save time. Deliver modern experiences that stand out.

Start small. Master the existing blocks before building custom ones. Create a few patterns for your next project. Experiment with FSE on a personal site. Each step builds confidence and expertise. Before long, you'll wonder how you ever worked without these tools.

The market rewards developers who stay ahead of the curve. Clients increasingly expect block-based solutions. Agencies need developers who understand modern WordPress. Position yourself as an expert now, while many developers still resist the change. Your future self will thank you.

Remember, this journey connects to broader trends in WordPress development. The same forward-thinking approach that drives block development applies to other emerging areas. Whether you're building blocks, creating headless solutions, or exploring new WordPress APIs, you're part of WordPress's exciting evolution.

Take action today. Set up that development environment. Build your first custom block. Create patterns for your current projects. The best time to master these skills was when Gutenberg launched. The second-best time is now.

References

Building Custom Gutenberg Blocks: The Definitive Block Development Tutorial

WordPress theme.json Guide: Everything You Need to Know

Global Styles & theme.json

A Beginner's Guide to Custom Gutenberg Block Development

Intro to Gutenberg Block Development

Exercise: Creating theme.json

Like this project

Posted Jul 6, 2025

Go from a WordPress user to a Block-Boss. This guide covers everything freelancers need to know about mastering the Gutenberg block editor and Full-Site Editing (FSE).

Likes

Views

Block-Boss Level: A Freelancer's Guide to Mastering Gutenberg & Full-Site Editing

Block-Boss Level: A Freelancer's Guide to Mastering Gutenberg & Full-Site Editing

What Are Gutenberg and Full-Site Editing (FSE)?

From Classic Editor to Block Editor: A Brief History

FSE Explained: Block Themes, Templates, and Global Styles

Becoming a Power User of the Block Editor

Advanced Block Features You Might Be Missing

Creating and Using Block Patterns

The Anatomy of a Custom Block

Setting Up Your Development Environment

Understanding block.json

The edit and save Components in React

Styling Your Blocks: From Inline to Global

Best Practices for Block-Specific CSS

Leveraging theme.json for Consistent Design

Unlocking Client Value with FSE

Building Flexible and Empowering Client Sites

Introduction to Migrating a Classic Theme

Conclusion

References

Join 50k+ companies and 1M+ independents

The `edit` and `save` Components in React