Your mind and imagination—two things which are related, but not really the same—have to recycle themselves, at least in regard to this one particular work. My advice is that you take a couple of days off—go fishing, go kayaking, do a jigsaw puzzle—and then go to work on something else. Something shorter, preferably, and something that’s a complete change of direction and pace from your newly finished book. (I wrote some pretty good novellas, “The Body” and “Apt Pupil” among them, between drafts of longer works like The Dead Zone and The Dark Half.)