I pesonally liked to do lateral raises to build that nice side mass on the delts, I would do burnout sets after I got done with military dumbell press and upright rows.... I just felt they did a good job in finishing off all the fibers in the delts and stimulating overall growth...
Heavy DB presses with good form seems to be the best mass builder for your shoulders. You could also try some of the shoulder press machines, they arent bad. Recently I have been doing more upright rows(they sorta hurt my wrists so I dont do them too often) and my shoulders have been getting real sore...so variation is also key. Keep switching it up and going as heavy as you can while still keeping strict form.