Although A Director Prepares: Seven Essays on Art and Theatre is aimed at directors and others interested in theatre, there is much that is useful for the writer. I've often heard about using method acting techniques to get inside a character. I was an actor, and then became a director, and I find the directorial approach more useful, particularly for revision.
"When in doubt, when you are lost, don't stop. Instead, concentrate on detail. Look around, find a detail to concentrate on, and do that. Forget the big picture for a while. Just put your energy into the details of what is already there. The big picture will eventually open up and reveal itself if you can stay out of the way for a while. It won't open up if you stop. You have to stay involved but you don't always have to stay involved with the big picture." p. 135
If you have the chance, do go see the productions of Anne Bogart's SITI Company. Her Midsummer Night's Dream was the best I have ever seen, and I've seen dozens of productions of Dream.