The best thing we can do after a first draft is to let it sit. Do not pick it up. Do not think about it. Let it sit for a month or longer while you work on something else (another story, perhaps). See, the mind needs the rest. When we do pick it up later, the mind is fresh, and we then catch all the glaring mistakes that we didn’t notice before. Have you ever been looking for something in the house, in a drawer for instance, and just couldn’t seem to find it? Then a day later, there it is, right where you thought it was. Your mind passed it over, convinced you that it wasn’t there. This is the same concept. Take a break after the first draft; it’s the best thing you can do for your story.