I don't prep. With a teething infant, a large roster of guitar students, a small graphic design business, and a wife who feels the creative urge as strongly as I do, I don't have much spare time. The small quantity of time I'm able to steal from the rest of my life is going to be spent painting, or composing a song, or writing an article for an awesome gaming blog, not prepping for a game.
I'm an improvisational game master. I play by ear. I fly by the seat of my pants.
I don't go into a game blind, however. When I sit down to run a game, I have a bandoleer of tools and techniques that help me and my players create a story out of nothing. They pretty much amount to this: let the players do all the work for you.
