Ana muses about how characters' motivations help with plotting a story.
As I understand it, in a character driven story, the protagonist has to have something that motivates her (or him) at the beginning of the story. A goal or a problem.
Problems could be boredom. Paralyzing self-doubt. A threat from a dystopian overlord. Lack of money. Abusive boyfriend. Lack of money. Cruel step-mother.
Goals: make partner in the law firm. Win a beauty pageant. Marry the man she loves--but doesn't know she exists. Meet the man of her dreams. Ignore her marriage-obsessed mother and not think about men at all. Finish her current job and take a badly needed vacation. Go on the honeymoon trip even though she got left at the altar.
Once the story world in introduced, the protagonist's "plan" to achieving her initial goal defines Act 1 of the story. Then things have to get complicated. A new character appears who blocks her path, who interrupts with his mere presence, who won't take no for an answer.
Thinking of the what-ifs--what if he does this, then she would do this-- helps me draft a story arc. Different arcs come to mind, but gradually one rises to the top of the heap. Since all stories are the archetypal themes retold in a new way, I settle on one and start outlining.
The outline will get revised after the first attempt as well as as I write. New ideas pop up. Dead ends become clear. The first draft is round, but the character's motivations and goals are more set. I know the characters better. And I see more obstacles to throw in her path.