A Ruth by any other name, by Catriona

How do you come up with character personality sketches for your books - do you plunge in and let your characters develop on the page, use real life people as inspiration, turn to personality frameworks like the enneagram? Especially for those who've written a lot of previous books - how do you keep your new characters from looking and feeling like your old ones?

I too have no clue what "enneagram" is, so that's that out of the way.

Next, I want to say how much I love Mary Higgins Clark, whos...