Use heavy negatives on the dip machine for triceps. I absolutely love doing these. It's an effective, safe way to overload your triceps with heavy loads.
Have someone help you do the concentric portion of the lift. Then do the eccentric or negative portion by yourself. Take a few seconds to lower the weight.
There's more to squatting than just getting under a heavy bar and popping a couple of blood vessels in your eye. Here are a few little-known variations of the king of lifts.