Not sure I have written enough long stuff to have a particular spot, but I have re-written chapters 1 – 3 of my current one because they were nagging at me for more content and backstory so that later chapters and character motivations make more sense. The rewrite happened after ch 8 – and probably has more to do with procrastinitis than discipline.

For shorts, my usualy medium, it just flows to the end, then I edit.

I probably should but I write the whole thing then determine if it still fits with where the story ended up going. I often completely rewrite the beginning at that point or, more frequently, lop off the first few chapters because that wasn’t the best starting place for the story.

I used to write, start to finish, no pause for breath, and only afterward scour through for crappy writing. Now I’m more of a perfectionist and can’t move forward unless each paragraph is as good as I can get it without a second eye. The negative of this: I write much slower and produce less. The positive of this: My work is much better quality than it used to be and I have far less editing to do. I also have a horrid habit of reading back through what I wrote the day before, before I can start writing to add to it. This, too, has it downside: by the time I complete it, I’ve read the opening about 30 times (because I go way back to the beginning until I decide it’s simply to far to go back), which then leaves me wondering if the opening is as half-decent as I initially thought. I doubt I’ll change how I work, but it does irritate the hell out of me.