Throughout my career, my general pattern has been to start each day's work by editing, polishing, and revising what I wrote the day before. I can't argue with the way it's turned out. On occasion, when deadlines were tight, I've been known to just start typing where I left off the day before and rely on Livia to fix any mistakes I make. It certainly helps to have a fine editor in the same house, so that she can say "What happened to the other dead body?" or "This sentence doesn't make any sense" or "You're not going to have the hero get hit on the head and knocked out again, are you?"
I've also, at times, written something straight through and then gone back to the first and edited the whole thing, and I'm wondering if that might not actually be the best way to approach it. I think when you read the whole book in a relatively short period of time, you might see things you'd miss if you were just rereading small chunks every day. But I don't know. When it comes to writing, my rule is whatever works is what works, if that makes sense. I'm curious anyway about what you writer-types out there think. Is it better to revise every day, or wait until you're finished and revise the whole thing?