Writing a first draft is a lot like an act of prayer. You're stuffing your conscious self behind a wall of surrender and then waiting, hoping, for the spirit to give rise to the truth that is beyond conjuring or controlling. You're constantly battling distractions the conscious mind wants to assert: "Do this. No, don't do that. That's a dumb idea. This'll never work. Don't you need to feed the cats?"
In prayer, as in writing, you have to guard against the conscious self, catch it off-balance with a change of scenery, stretch it out with physical exercise.
Sometimes you have to cry, make it feel bad so it'll go sit in the corner for a while and let the subconscious, the Imagination, out to play. I know cause I spent 3 hours yesterday with my notebook in my lap, wordless.
Brenda Ueland said it well in her book If You Want to Write:
You have the creative impulse.
But the ardor for it is inhibited and dried up by many things; as I said, by criticism, self-doubt, duty, nervous fear which expresses itself in merely external action like running up and downstairs and scratching items off lists and thinking you are being efficient; by anxiety about making a living, by fear of not excelling.
Now this creative power I think is the Holy Ghost. My theology may not be very accurate but that is how I think of it. I know that William Blake called this creative power the Imagination and he said it was God. ...
Now Blake thought that this creative power should be kept alive in all people for all of their lives. And so do I. Why? Because it is life itself. It is the Spirit. In fact it is the only important thing about us. The rest of us is legs and stomach, materialistic cravings and fears. How do we keep it alive? By using it, by letting it out, by giving some time to it.
Quoting W.B. again, she later said,
"Reason, or All we have known, is not the same it shall be when we know More." And how will we know more? Only through the Imagination which comes from God, and from which the prophets and all great people have spoken.
I can't think or reason my way toward a good story, or well-drawn characters. When I write what I think would make a good story, then put the pen down and read, there's no life in it.
When I wait, when I give my imagination time to come out and play, when after 3 hours I finally cry the self-conscious conscious self away, that's when the authentic story shows itself to me. It still takes work--no golden-egged goose here--but I'm learning that in the work is waiting, praying, writing, and playing.
Quotes from pages 10 and 170, respectively, in the 1987 Graywolf Press edition.