Throwing Clubs

This may not do much to help you win, but it sure makes you feel better. Grip the club with two hands and let her rip. Aim for trees and make sure you get a good trajectory. Some snooty players may get perturbed by your childish actions, but that can only help your chances. Don't throw your good clubs. Keep a junker in your bag just for throwing if you need to. You can throw your club at your opponent and act like it was an accident, but they may just leave. Default victory!

Auditory Distractions

Say things like "don't miss" as they line up, or cough in middle of their backswing. Every time they swing, you should be talking to them. Learn what bothers them and use it. Swear and tell dirty jokes if you are playing a priest. Make fun of a Norwegian's accent. Give them bad advise about their swing or the course. Once you get on them just a little bit, they will start mentally blaming you for all of their bad shots. If they ask you to stop, pretend you didn't hear them or just ignore them.

Visual Distractions

A couple of fun ones here. Stand in your opponents peripheral vision when they are lining up to hit. Start taking practice swings during their shot. Their eyes will be naturally drawn to the movement during their swing, and they will take their eye off the ball. Get on the green first and stand by the flag. Grab the flagstick and hold it a five feet from the hole. When they shoot they won't know any better and will be aiming for the stick instead of the hole. When your opponent is putting, walk around the green by the hole. It will distract him from his target.