If you're like me you have a love/hate relationship with your work. You get really excited about a sentence you write or a cool idea or a cool new character. You feel good about it all. Then you feel really bad. Then good again. It's great. It's terrible. But as you work through drafts, you feel better. The story seems to come together. Many aspects of the work that were out of focus are more in focus. You improve your sentences. Your characters are more in the scenes, more real, more developed. They have depth--yes they do. It all seems to be going somewhere. Hallelujah.
And then there comes the moment when you think you are finished. You have done everything you can. You're done.
Do not be fooled.
If you're like me, you're seeing a manuscript that has been greatly improved by many drafts. You're seeing something that is so, so much better than that first draft. You're thinking about the cool things in the manuscript and accepting the weakness as not all that weak. You want to believe they're small and of little consequence, like a few tiny chips in armor. Nothing to worry about. And the cool things. Come on, so cool--it's good--a good story.
This is the point where you need at least a month to get far enough away from the manuscript that you can see that though the cool things might still be cool, those weaknesses of the manuscript are real and need to be worked on. And you will also see that there are other problems you couldn't see before. Sure, it's a little disappointing that after many drafts there are still a lot of areas that need work. But doing this final revision, working on these weaknesses, can be the difference between a pretty good manuscript and a very good one.
Give yourself time and distance from your work AFTER you think it's ready to go. Doing this has really helped me.