Like many other writers, I can see the warts in my writing all too well once I've let them sit and ferment. Sometimes I'm able to get in there and wash away the worst of them. Other times I want to suit up and dig them all out of the swamp.
That impulse -- pull all the mistakes out until it's a beautiful clean field of prose -- is a dangerous one. It creates a stall in the forward progress. Don't believe me? Find a flat, unplanted acre of land and try to pick out all the rocks on your first pass, by hand. It's a similar task in its immensity. Pull up a hundred rocks and you discover two hundred just below the surface.
I've learned, through bashing my head more times than I can count, that engineering perfection in one pass, or even expecting it after a hundred, is a fool's goal. A waste of time that could better be spent elsewhere. Perfection won't ever come.
What does work (for me), when I remember to let it happen, is a series of rounds of editing. Replace the worst ten percent, let it sit, replace the next worst ten percent -- that sort of idea. Let the benefit of multiple glances, multiples attempts at improvement, begin to pull the characters, the actions, the story into shape.
On my worst days, greedy (for perfection) and impatient (of the time it takes to improve a chapter slowly, round by round), I sit almost unable to do anything. I want so much I can't even get a single bite into my mouth. I want to swallow one whole elephant without having to chew. On the better days, with impatience for any forward progress at all, I take it bit by bit, chewing, examining, swallowing.
It'll get there, I have to remind myself. It's not there yet, but it'll be there soon. If I help it. If I work it over with care and patience. Bit by bit.