As far as comics, I limit my draft layers as much as possible to save memory and sanity
1) thumbnails sketches
2) composition - building up characters and scenes
3) text/speech layer - change panel layout cause everything's always too cramped
4) line layer - I don't often go back and edit, I stick with the first or second attempt
then color, render, sleep, and publish whatever I end up with.
I know I should be more diligent about editing and formatting, but it gets old staring at the same panels for several days and I'd rather progress forward than backward, no matter how iffy it looks. Lingering on making things perfect is a quick way to lose morale, in my experience.
Hadn't written anything in a while, so I forget how long it took and how many drafts (one story of mine took ten years before I abandoned it), but I know I'd be working on it forever if I tried (which is why I chose comics)