Want to get your shoulders stronger with minimal equipment? Check out these two
overhead variations that are staple exercises in my own training:
 

1) Pike Push-Ups:

Easily one of the most “bang for your buck” shoulder exercises
that requires literally zero equipment and can be done anytime anywhere. The
Pike Push-up is deceptively challenging even for advanced lifters, so make sure
to modify the exercise by reducing the angle at your hips or reducing the range of
motion as needed. Fully extend the arms and get your head through at the top of
each rep.
 

2) The DB Z-Press-

 The DB Z-Press is undoubtedly the best/most effective
pressing variation if training with only 2 moderate weight dumbbells. By pressing
in a seated position with your legs straight in front of your body, you eliminate
any arch during the press, forcing the shoulders to do the brunt of the work.
Other variations such as the single arm Z-press leaving the non-working arm up
or simply doing a single arm Z-Press with one DB are great alternatives as well.