Characters and revision

For me, the later drafts of a project involve going deeper and "rounder" with the characters, looking for more details, stripping away their defenses (and mine). Studying their motives, analyzing their hobbies and habits. I love it when characters surprise me, because then I can discover why they did what they did.

This is always much harder than I imagine it will be at the outset. I think I know my characters in the first draft, and then by the third draft I've identified blank spaces, flat a...