In chapter two of the book, we learn about characterization, and to a degree the lesson is the same: show, don’t tell. Let the action and the (natural) dialogue help the readers form their own opinions sf the characters.
The basic idea is to avoid introducing your character all at once, by describing them and their history and the important things about them when we meet them. That slows down or stops the action. But if you show us the character a little at a time, the readers can interpret the character as they see fit.
Some specific things to avoid:
–Flashbacks. These stop the present action all at once.
–Long bits of exposition about the character.
–Presenting already arrived-at conclusions about the character.
–Absolutely don’t use maid and butler dialogue, or “feather duster.”
–Don’t tell about characteristics that show up in dialogue and action.
Rather than any of the above techniques, establish your character unobtrusively.
–Show characters saying and doing things.
–Write about what your character thinks about things.
–Give only as much background, history, or characterization as is absolutely necessary.
–When having to explain a new culture, let reader see them in real life– not lengthy exposition.
In the end, it is the same lesson as chapter one: know when to show and tell. And in the case of characters, it will almost always be better to show.