Norman Mailer in The Spooky Art -- "Rewriting is where your working experience over the years has its day. There comes a time when you know how to get the maximum out of what you've done. The only way to accelerate this skill when you are young is to have the courage to look at it when you're about ready to destroy it. If something still comes through, then it may well have the merit to be worked upon further. It is also not bad to read things at the top of your feelings in order to get a sense of what the maximum might be. If nothing else, all this will give you a tolerance for the extraordinary range of reaction you can receive in the classroom. You realize that the people who don't like your work aren't necessarily evil and the people who love your stuff don't have to be altogether illustrious."
I was in a band once where, at one rehearsal, we'd sound great, so we'd show up for the next rehearsal with incredibly high expectations and, to our disappointment, sound pretty chaotic. Then we'd came back the next week with lower expectations, and our sound seemed perfect again. Before we could escape that cycle, I fell out with the frontman, and was thrown out of the band - maybe they found it easier to solve the problem without me.
Editing can be blissful. Excising a single line can make a whole page seem startlingly better-written. Replacing one verb with another verb can make the author appear exponentially more observant.
Other drafts bring less satisfaction. An old sculptor once advised the young Auguste Rodin that, if one's work isn't going right, one should try dropping it on the floor and see how it looks then. Ths advice is tricky to apply to novels, but the principle of getting rid of anything that sticks out too much might still be a sound one.