One point to consider- the triceps are the deciding factor in any type of press: OH, bench, incline, etc. They are equally as important as deltoids when pressing (not including push press, as that has a lot of leg drive to get through the sticking point where the tris take over). I am sure that adding compound lifts like OHP, inclines, db shoulder presses, ect. are beneficial as long as you aren't overtraing, but tricep extensions and board presses will help your shoulder press as much as direct delt work, IMO. Oh, and I think rear/lateral raises/db cleans/rotator work are very worthwhile for structurally balanced shoulders-- OH presses work the anterior and side delts a hell of a lot more than the rear delts/upper back.