You protect your shoulders by avoiding lifts where you are pushing over top your head. I do a lot of Lateral raises, front raises, and rear delt fly's to see my shoulders grow. Another thing is working shoulders after you have done shrugs for traps. If your traps are already tired your less likely to use them as you are trying to force weights up in a lateral raise. Also big traps tend to compliment and push those shoulder caps out. Probably just an optical thing, but my shoulder caps seem to bulge the closer my traps get to my ears.