Collection pages need copy too, not just product pages.
Two lines above the grid: what's in the collection and who it's for.
Does your shop's collection page say anything yet?
Put the key fact first in your product description.
What would a buyer ask before anything else? Size, fit, what's included?
Answer it in the first line.
The story and details can follow.
What's the first question a buyer asks about yours?
Read your headline out loud.
If you'd never say it to a person, rewrite it.
Keep it short and put the important words first.
If you stumble while reading it, so will your reader.
Which of your headlines would you never say out loud?