If you don't obey the speed limit, sooner or later, you'll be pulled over. When that happens, your rapport with the officer could make or break your chances of avoiding a citation.
Get your temper under control and avoid courting suspicion. Remember, when an officer approaches a vehicle, he or she is entering an unknown and potentially hazardous situation. Anything you can do to relieve the officer's apprehension is likely to work in your favor, so keep your hands on the wheel as he or she approaches. Moving around a lot suggests that you're going for a weapon or that you're stashing something, which could be construed as probable cause to search or impound your vehicle.
Make eye contact. It indicates you have nothing to hide. In fact, making eye contact with an officer as you pass the patrol car can also help you avoid a ticket. Don't admit anything, but be genuinely polite, forthright and cooperative. Excuses aren't likely to work, and arguing definitely won't. But if you have a good reason for speeding, use it.
Finally, keep your car's interior and your own appearance as clean as possible. Looking like the Unabomber won't help your case.