All right, so you shut the door, and you write down a first draft, at white heat, because that energy has been growing in you all through the prewriting stage and when released at last, is incandescent. You trust yourself and the story and you write.
[...]
Then it cools down and you cool down, and arrive, probably somewhat chilled and rueful, at the next stage. Your story is full of ugly, stupid bits. You distrust it now, and that's as it should be. But you still have to trust yourself. You have to know that you can make it better. Unless you're a genius or have extremely low standards, composition is followed by critical, patient revision, with the thinking mind turned on.
I can trust myself to write my story at white heat without asking any questions of it - if I know my craft through practice - if I have at least a sense of where this story's going - and if when it's got there, I'm willing to turn right round and go over it and over it, word by word, idea by idea, testing and proving it till it goes right. Till all of it goes right.