1. Read it out loud. Does it sound natural? Does it sound consistent? Does it sound like you're trying too hard/not hard enough?
2. Make a synopsis of your story. Does it have a beginning building to a middle, building to a slam-bang end? If not, time to rethink.
3. List the most important events of the story. Now shuffle them into a new order. (i.e. What happens if the Prince discovers the identity of the Princess before the masked ball?) Better storytelling? Worse? Worth experimenting with?
4. If you're a typist, try writing a scene by hand. If you're a hand-writer, try typing a scene.
5. Take that most recent, tricky scene. Rewrite it from someone else's point of view. Rewrite it from multiple points of view at once. Rewrite it first-person or third-person. See anything new?
6. Role reversal: Write a scene with your antagonist as your hero and your hero as your antagonist. See anything new?
7. Print out your document and bind it like a book. Do the errors suddenly pop out at you? The slow passages? The repetitive passages?
8. Write an editorial letter to yourself. Let Editor You inform the Writer You of your strengths and your weaknesses, including suggestions for improvement.
9. Write about what happened before the story took place. Write about what happens after the story is over.
10. And, if you really are getting too close the manuscript and having a wretched time seeing it with fresh eyes . . . try reading it backwards, last scene first, etc. Anything jump out at you?