I'm sure my weakest joints are my shoulder, and as they say, you're only as strong as your weakest link. I've never had any issues beyond occasionally feeling some minor shoulder joint pain, in which case I reluctantly lay off until it gets better. Sometimes it's caused after strenuous training, and other times it happens after a night of sleeping on my side (which comes from compressing the joint, I suppose). It happens in either shoulder.
I've been advancing cautiously, not pushing it, resting when I think I should. Can anyone offer some shoulder prehab movements along the lines of wrist pushups and the like for some specific conditioning?