It's hard to explain the place of revision in my writing since I'm neither an "organic" nor an "outline" writer. Put simply, I always spend a considerable amount of time planning such details as worldbuilding, characterisation, and basic story outlines before I write, but then continue to develop all of them as I write. As a result, I normally end up having a much better (or at least more detailed) conception of my stories as a whole when I've finished writing the first draft--but the earlier parts of the story are often not entirely consistent with the later, more fleshed-out parts. Sometimes I go back and revise as I write to reduce this discrepancy before it gets too big. Sometimes I don't bother and simply rewrite the earlier portions (or the whole story!) later on.
So is there any consistency in my approach to revision and rewriting? Certainly! One thing has never, ever changed: every story I write has demanded its own unique approach to revision and rewriting, so I've learned not to worry if I can't do things the same way twice.
(Posted as part of the Forward Motion Writers' Merry-Go-Round Blog Tour)