That was the challenge with Beyond Borders, a documentary that was never really filmed as a documentary, and so had to be pieced together and moulded into a story that made the most of the existing footage, while filling in the story gaps with voice over.
Editor Nick Lear brought me into the project when he had managed to get a good extended cut of the film together, but needed someone to smooth over the edges, figure out some of story flow, write additional VO... but most importantly, shave a good 30 to 40 minutes off the running time.