For big cannonball deltoids, it is important not to overtrain the muscle which is relatively small and used in almost every other exercise for assistance and rotation. I suggest 1 exercise of heavy presses, 1 lateral raising movement and 1 rear deltoid isolation movement. This is all you need to develop big delts in terms of direct isolation movements. Any more and I guarantee you are overtraining the muscles and inhibiting growth. If your delts are really lagging I suggest taking 14-21 days off of ANY direct delt training. This will allow optimal rest time of the muscle as well as allow for a massive growth inciting shock once you go back to direct isolation training of the deltoids.
