To alleviate the flat taste that water can develop from sitting in a plastic bottle - drop in a slice of lemon or lime. This is especially refreshing during hot weather. One slice is good for the whole day!!
Always put your left foot down when stopping, to prevent chainring "tattoos" on your right leg.
Practice making a H-s-s-s-, H-s-s-s sound to imitate a puctured tire. If done convincingly, you can get your biking buddy to let up and look at his tires, giving you a chance to get ahead. (But you'd never do that, would you?)