...try Single Arm Dumbbell Side laterals, keep one arm tucked close to your body while the other arm is doing the lateral movement....no swinging of the weight, elbow slightly bend throughout the movement....standing up... I do 6 sets of 10 twice a week....it adds crazy ass bulk to the lateral part of the deltoid. Also, do it in the beginning of your Delt workout...then follow with a couple sets of Mil presses or DB presses.
Ray Johnson