If you are talking about pressing power, you are talking about the triceps. Building massive triceps, does not necessarily mean you are improving their ability to move weight. And if we are talking about power, we are talking about moving the weight quickly.
If you really want more pressing power, you can’t be messing around with skull crushers and tricep kickbacks. You have to perform compound movements - plain and simple.
Examples include: Close grip bench press, log press, floor press, neutral grip db bench, wheel barrow plyo hops, inverted wall bodyweight press ups.
And you can’t forget about balancing the joint, anterior and posterior. That improves the integrity of the joint, the strength potential and decreases the chance for injury, chronic or acute. So you have to hit movements that target the muscles involved in stabilizing, antagonistically counteracting and keeping the shoulder joint healthy and strong.
Exercises like: Face pulls, posterior flyes, push-ups plus, standing scarecrows, external rotations, reach roll and lift, Y,T,W and L.