A word about the dirty draft, from Anne Lamott.
"Almost all good writing begins with terrible first efforts. You need to start somewhere. Start by getting something -- anything -- down on paper. A friend of mine says that the first draft is the down draft -- you just get it down. The second draft is the up draft -- you fix it up. You try to say what you have to say more accurately. And the third draft is the dental draft, where you check every tooth, to see if it's loose or cramped or decayed, or even, God help us, healthy." - Anne Lamott