Power for shoulders is difficult. This is a small group of muscles with a delicate joint that will rebel from too much abuse.
Front presses can generate some decent weight if you pull in other muscle groups for addition push. I'm thinking standing front presses.
Oppose this to strict seated behind the neck presses, where there is little or no additional help coming in.
Another consideration is the ease of overtraining this group. They get hit so much with other body parts.
All that said ... I got the best results from the following simple sequence:
(1) Seated behind neck presses. 3 x 6
(2) One arm db side laterals 3 x 6
(3) Bent db side laterals. 3 x 6
(4) Shrugs 3 x 6
I'd do a series of warm ups that took the joint through an easy full rotation.
The last set could be drops or partials so I was constantly pushing the weight higher, especially 1 and 4.
This routine was done between chest and tri's ... the traditional push day.
Notice 6 reps. I found that more than 6 burned up the muscle and the clav bones would show. Less didn't build enough. Learned this from Larry Scott.