How would you discipline a teenage child?

The teenage years of anyone's life is perhaps the most tumultuous. It's at once the most confusing, exciting, traumatic and no one can really blame them from acting out; after all we have all been teenagers and know what it's like. The most important thing about discipline, no matter the age, is making the recipient understand why your doing it. Always focus on the "why" and not the "how." Teenagers may not understand it at first, but they will sooner or later.