If you truly want to build big shoulders then you will have to add handstand push-ups to your arsenal. There is a reason why Olympic gymnasts have killer delts.
Handstand push ups are an advanced level exercise but can be modified to accommodate novice or intermediate lifters.
The easiest way to do handstand push ups is to prop yourself up against the wall [as a spot] eventually you’ll want to increase your range of motion by placing your hands on boxes and lower your head between them. This is the ultimate pressing exercise and should be included for some massive shoulder development and full body strength and athleticism.
Patience is a must.
You might not be able to do 1 your first time out and that’s ok. Start by working to holding your bodyweight in the handstand position for 60 seconds. Then you can start training the eccentric portion of the movement lowering yourself slowly [take 5 secs to lower]- do 5 sets of 1 reps working up to 5 sets of 3 reps lowering in 6-8 seconds. Patience is a must when it comes to progression so take your time. When you can do 8-10 reps that is when you can try increasing the range of motion as I mentioned above.