The day I can't write, I sleep. It'll come back eventually. I think a lot of writers expect to make a perfect book on the first attempt, but that's not the case. I write from the ground up, the first draft is awful. But just like a house, it's a foundation (though not a very beautiful one), the second draft will have some cement. By the third draft, it's got walls. By the fourth and fifth, it's looking more like a mansion and finally, I can move in and decorate. So in other words...allow the first draft to just be a draft, let it stink, that's what the editing process is for.