I would concentrate on doing laterals to pack as much size on as you can.Width is what you want.

With all body parts I start out with the heavest power type movements. For shoulders I start with military presses then move into bent lateral raise, side laterals and upright rows.

for Upright rows and laterals.. how do you guys reduce trap involvement?

With upright rows I use a wide grip (a little wider than shoulder width). The closer your hands are together the more it will hit the traps. As far a laterals go like eveything else I concentrate on form. If you are using slow controlled movements and not swinging the weight you shouln't hit the traps much at all.

Pressing movements. Military press, bench press, and incline press have all helped my shoulder size.