Character Development

This might be a long shot, but I was wondering if anyone on here had any good ideas, exercises, and or resources on character development. This could concern design alone but, I'm also curious about fleshing out a character's personality. Is there a way to organize this? Or is it something people can just maintain in their head and just KNOW how a character would act in any given situation? As far as the physical design goes, I remember a long time ago Mr. Lafferty, you did a daily on character design where you discussed drawing the character on what I would call a grid format from 3 different angles. I was wondering if you'd developed any new techniques to help since then. As well as, if you had any advice from when you were developing Emma for your comic, or others, that I could learn from I would greatly appreciate it.