Weighted Bench Dips
This is an exercise that can be modified and copied to fit whatever situation you're in. It's an excellent tricep exercise and can be adapted to help increase your tricep size and strength no matter experience level.
You need to be careful with this exercise though. It's important to reach parallel with your elbows to the bench, but be conscious of your ligaments and joints. If you feel the ache in your joints and not your muscle, regroup and tweak your technique until it's fixed or lighten the weight.