Start with dumbbell in weaker arm. Place same side knee on bench and opposite hand in front of you. Your forearm should be pointed towards the floor with a 90-degree angle formed between your forearm and upper arm. Exhale and push your tricep to lift the weight until the arm is fully extended. Pause and inhale while lowering the weight. Repeat this range of motion until all reps are completed. Then change arm & knee on bench and repeat.