In displaying the psychology of your characters, minute particulars are essential. God save us from vague generalizations! Be sure not to discuss your hero's state of mind. Make it clear from his actions. Nor is it necessary to portray many main characters. Let two people be the center of gravity in your story: he and she.
Anton ChekhovThe world perishes not from bandits and fires, but from hatred, hostility, and all these petty squabbles.
Anton Chekhov