Tip #455: Character masks

People in real life wear masks to protect their real feelings and vulnerability.
Masks peeling away is a dramatic device

http://aerogrammestudio.com/2013/12/14/50-narrative-devices-for-non-fiction-storytellers/#more-5652 Slide 26

Tip #450: Finding sparks of life

When a particular character isn't coming to life, I... write out what s/he would say for themselves in an interview.

'Why I did this...'
'why I'm ging to do that...'
'Why I'm right...'

...The reasons and excuses aren't so important, but the perspective is... an assertion of {the character's} own perspective...

self-justifications... don't get into my novels. They do influence... the scene where a character is confronted by the truth about themselves.

http://writingtips.com.au/WRITING%20TIPS%20BRITISH%20version/downloads/wtipscontinuousUK.pdf p 63-64

Tip #445: Why character choice matters

There are very few situations where every human being on the planet will respond the same way, so the cascading series of unique choices they make — each time altering how the story goes — is what makes them — and the story — come alive.

When you’ve done it right, you’ll look at your story and realize that it would have been an altogether different story with any other character in the same situation.

http://www.aisteach.com/blog/?p=1205#more-1205

If you have some situations but no protagonist/antagonist, those situations (and how the characters got into and get out of them) help define your characters.

If you know your characters try asking yourself occasionally what they wouldn't do, and then work out why they'd do it.