Sometimes I write in a hurry and then do a lot of clean up. I judge how close I am getting to a finished work by the amount of change I make when I re-read a section. If I am moving paragraphs around, then I am a long ways from complete. If I am removing sentences, then I am close. I find the delete key to be the most valuable key on my keyboard when I do editing. Once I get down to only a few word replacements, then I think I have a draft ready to be shared. And when I get to where I replace a word in one read through, only to put it back in the next read through, then I know I am stuck in a perfectionist loop and I need to stop.