On a blog for the Pixar Touch, a documentary about the history of Pixar, they published a collection of rules for good stories originally tweeted by Emma Coats a Pixary Story Artist.
Some good ones:
#5: Simplify. Focus. Combine characters. Hop over detours. You’ll feel like you’re losing valuable stuff but it sets you free.
#6: What is your character good at, comfortable with? Throw the polar opposite at them. Challenge them. How do they deal?
#17: No work is ever wasted. If it’s not working, let go and move on - it’ll come back around to be useful later.
See http://www.pixartouchbook.com/blog/2011/5/15/pixar-story-rules-one-version.html for the rest.
