I wanted to share a particularly helpful bit of information I recently learned from an editor I follow.
As you know, I've been revising a MS for my agent, per request. And she had some very instructive, insightful things to say about it, but she pointed out (and it was immediately clear) that certain aspects of some of my characters were not fully imagined.
As you can think, this filled me with chagrin. Those darn secondary characters. They played good parts in the story, but I only showed the parts they played, and not their motivations. And this was hurting the story more than I ever suspected it could do.
So I thought. And thought. And finally I came up with how I could deal with this solution. I made a character sheet for each. I know. Uncool. I always mocked those types of things, but here I am using it. And you know what? It helped enormously.
In fact, I think it improved the story beyond what I had already thought was a darn good one. It was fantastic!
So just for reference, I'm including my main questions here for my secondary characters in case it might help you:
1. Character name
2. Character motivation in story
3. Character conflict
4. Character conflict with POV
5. Character resolution
Hope this helps you as much as it helped me! And tell me - do you do something like this at the end, in your revision process?