Skull crushers with a STRETCH
Tricep training tip:
Lying dumbbell tricep extensions (db skull crushers lol) are a great way to engage the long head of the tricep. The triceps long head attaches to the shoulder blade which means it’s has the action of doing shoulder extension.
So if all your tricep movements are using isometric hold at the shoulder joint, your focusing on using mostly lateral head and medial head. By including a shoulder extension into the move you engage the long head more. Then superseding it with pull overs with the elbow bent, you keep pulling with the long head even after the medial and lateral head have fatigued.
The tricep thickness of the upper upper arm is made up a lot of a well developed long head. So include a shoulder extension movement to your next tricep session!