Fiction: Characterization
Characterization is the qualities and attributes a writer uses to define the character. These qualities can include, but are not limited to a character's physical, social, mental, and spirtual, and make-up. A well-defined character can liven up a story or help define other aspects of your story like plot or conflict.
Exercise: 20 Questions
Brainstorm 20 questions that might be included in an interview. Work out how a minor character in your story would answer these questions. See if you can include the new details in an existing or new scene.