Some from
http://screenwritingtips.blcklst.com/ I've enjoyed recently:
One of the best ways to find logic problems is to go through your script and ask, “Why now?”. (An ancient evil awakens! Fine, but why now? The mentor betrays the protagonist to his enemies! Okay, but why now?)
For complex scenes, set yourself an objective. This can be a specific moment which you want to reach in that scene. For example: “The moment when the protagonist realizes how she feels about Mike”, “The moment when Bob starts to see Jane as a potential ally”, etc.
When searching for something to cut, start looking in Act One. All that setup you thought you needed? Just training wheels. If you’re giving the audience the same information later, then you don’t need it at the start.