Austen creates characters with contrasting opinions, personalities, and values.
This provides her with so many opportunities to show rather than tell and to forward her subplots. She uses this strategy frequently throughout Pride and Prejudice (and all of her books) to excellent effect.
Darcy: “Mr. Wickham is blessed with such happy manners as may ensure his making friends—whether he may be equally capable of retaining them, is less certain.”
Contrast your characters and …
Within one scene, you can compare two characters’ actions and behavior which provides an excellent opportunity to show their personalities. This is particularly useful if you’re introducing your characters for the first time.
Two characters (even best friends) may disagree on a topic, and by each discussing their point of view, you can create conflict and tension and subtly push forward a subplot.
You can have two characters witness the same event - and each can come to very different conclusions. As the author, you can ensure one is right and the other wrong, which can be very effective in creating or seeding future obstacles.