Tricep Kick-Back Steps:
Place one knee, shin and foot on a flat bench and bend over to keep your torso parallel to the floor.
Grasp the head of the bench with your fingertips.
In the outside handhold a dumbbell. Pick a weight with which you can comfortably manage 12-15 reps.
Press and hold that dumbbell-holding arm against your side, with a 90° bend at the elbow.
Straighten your arm backwards until it is parallel to the floor. Contract your triceps at that top portion of the lift. Slowly lower until your arm is back at the 90° angle.
Repeat for 12-15 reps, then switch arms.