In order to create complete, full shoulders, you must perform the main mass building exercise correctly, the barbell press.  The barbell press is the mass building exercise for the shoulders as the bench press is for the chest.

The set up and the grip is the same. Place your hands on the bar by spacing your hands far enough apart so that when bar is lowered to your chin, your forearms will be perpendicular to the ground.  When the bar is lowered to your chin, you are in full stretch.  Pressing the bar to the top (or the contraction portion of the exercise), always squeeze your elbows up and aim towards an intersection point toward the top of your head. Never push straight up, if you do, you will most likely push up too quickly. By pushing up too fast, you run the risk of locking and snapping your elbows. This also adds an undue stress on the tendons and ligaments of the elbows.

Performing this exercise correctly is very important so you don’t damage your delicate rotator cuff.

Start with 8-10 reps to warm up the muscle and increase blood flow.  On your next set, up the weight and reduce reps to 6-8. You should be feeling maximum burn at about the 6^th rep (once you increase your weight) and then try to push out the last 2 for total muscle exhaustion. It’s wise to have someone spot you during this exercise to ensure that you are able to return the bench to a safe resting position on the bar behind you.