If you are ready for your triceps workout, after the warm up, you should start the workout with this exercise.
Sit down and pick one dumbbell with both your arms and make sure your body stays in one position. After you pick up the dumbbell, put your hands up straight over your head, like on picture 1.
That will be your starting position. When you are ready, start lowering the dumbbell behind your head. Make sure your hands can handle the weight of the dumbbell, and you should not move your upper hands.. When your elbows reach 90 degree angles, pause for 2 seconds like on picture 2, then start pushing the dumbbell back to your starting position.
Make this triceps workout in few series, each time adding more weight to the dumbbell. Your workout is done here.