I woke up the other night with what I think is finally the perfect opening for the first chapter of my "old" novel. I've lost count of the number of times I've rewritten this chapter, but it must be at least six or seven now.
I've found the best way for me to work is to just write and not get hung up on rewriting one chapter until it's perfect. YOu might never get past the first chapter!
What I do when I sit down to write is go over yesterday's work and make some changes if necessary. This gets me going and then I progress to the current day's chapter.
I only go back over chapter one after some time has gone by because then I see things that may need changing in light of something I've added. Plus the longer the time since I read it, the fresher and more objective my eye is.