Drafts and reviews

I do both. I tend to revise the beginning early on a few times as I'm working through the plot.. On my current novel, I stopped a third of a way through and went back and rewrote one of my POVs. And with my second POV, his scenes were so difficult to write early on that I edited them a few times before I would move on. Usually once I get about halfway through, I write through to the end. But I still stop and make changes along the way, I just tend to overlook sentence structure and grammar and other things that I easily fixed.

Makes for an interesting revision process because I'll fly through the first half and half hack away at the second half. Guess it works for me. And I'm always stopping (even towards the end) and going back and changing something in the beginning that popped into my mind. I guess I edit like a crazy person. It makes sense in my head.

Occasionally, if I can't think about what I want to write while working on a first draft, I'll take a look at previous chapters here and there. Otherwise, I wait till I've finished the draft, and take it chapter by chapter from there.

Welcome to AW by the way!

I've learned from experience that if I revise as I go, I never finish the book. I have to force myself to write the whole book and then go back to edit/rewrite.

However, one person's process may not be yours. Do what works for you. If you find you're not finishing your book because you're spending so much time fiddling with where to place a comma or double/triple-checking your spelling and whatnot, then you may need to reconsider your approach. If you're still making progress and beefing up your word count despite the above, even if it isn't at the speed you desire, I wouldn't worry about it so much.