More about back stories!
Sometimes, a brief story from the character’s past will establish something so you as a narrator don’t have to say it.
I thought it was really interesting to come across this article not long after reading the other one about info dumps.
The point is that there are a lot of ways to convey information.
Linking an anecdote to how a character feels in the present will explain a few things.
Instead of, “Jenny didn’t like surprises. They never ended well,” you can have, “Every time someone tried to surprise Jenny, she reacted badly. Usually it was because they were sneaking up behind her and trying to play ‘Guess Who?’, a game that always ended in the ‘who’ getting punched in the face or elbowed in the stomach.”
Much more interesting, eh?
Come up with a back story to a character trait you don’t have an explanation for. Not all character traits need an explanation, but it’s nice to have reasons for things sometimes.