Never get a hair cut, shave or trim your nails on the same day (or day before) your favorite sports team plays a game.
And no, I'm not kidding.
Generally, I don't believe in such things, but I have the annoying tendency to believe that my actions somehow affect the outcome of sporting events that I am merely watching.
In fact, they do! it is, like the Dark Side of the Force, unnatural...
My only superstitions have to do with how I can affect the outcome of sporting events based on my behavior. I know it’s complete BS, but I still have superstitions when I watch a Colts or Pacers game.
Never wear the opposing team's colors on the day of a game, either. Bad juju. Blue jeans are an exception however, because blue jeans trump team colors due to how common they are.