Tag: characters goals
You can listen to your cast of characters at any stage in the writing process, but it might be especially useful near the end when most of the story is fleshed out. It can be a good check of your story logic and add a last ingenious layer of polish.
When writing your next villain, give him or her as detailed a backstory as your protagonist. TV's Buffy and Firefly provide some great examples of well-developed, three-dimensional villains to use as inspiration.