Adding banded tension to your shoulder work is guaranteed to trigger new hypertrophy gains. Just grab a couple of resistance bands and wedge them under the bench for overhead dumbbell presses.
The key is to lift the dumbbells all the way up to the top and hold them there for a couple of seconds in the contracted position of each rep.
I'm going to describe a little 6-week program that I call Tsunami Training (I'll get to why I call it that a little later). It's based, for the most part, on training methodologies that I picked up from Ian King and Charles Poliquin, with some razzle-dazzle thrown in by myself.