One of the muscle groups which must be developed in order to complete your ripped and rounded shoulders are the deltoids. This group of shoulder muscles consists of the anterior deltoids (front), the posterior deltoids (back) and the medial or lateral deltoids (sides). Each of these should be given equal attention during weight training so that you develop a well balanced look to your shoulders.

Deltoid Exercises

Building Front Deltoids

The front (anterior) deltoids are used to move the shoulder forward.

One of the best exercises for building the anterior delts is the front raise. To achieve this exercise, hold a barbell or dumbbells with arms down at your sides. Slowly lift the weights straight up in front of you until they reach shoulder level. Slowly release and repeat.

Other top strength training exercises for the front deltoids include the shoulder press with dumbbells, military press, Arnold press, behind neck press and reclined shoulder press.

Building Rear Deltoids

The posterior deltoids provide the backward movement of the shoulder.
One of the best strength building exercises for the rear delts is the standing reverse fly. To perform this exercise, stand with feet placed approximately shoulder width apart and bend at the waist until your body forms a 90° angle with your torso horizontal to the floor. With arms hanging straight down and holding dumbbells in each hand, slowly raise your arms straight out and up until they make a straight plane with your shoulders. Be sure to keep your back straight when lifting. Slowly lower back to the starting position and repeat.
Other top strength training exercises for the back delts are the dumbbell row, rear delt row and rear lateral raise.

Building Side Deltoids

To complete the rounded look of your shoulders, you need to work out the medial, or lateral, deltoids. These side delts extend the arms out and up.

Dumbbell lateral raises work the side delts well. To accomplish this exercise, hold your arms down at your sides while grasping a dumbbell in each hand. Slowly raise both arms up and out to your sides until they reach shoulder level. Slowly release and repeat.
The other top strength training exercise for building your side deltoids is the upright row. Either dumbbells or weighted cable machines can be used to perform these exercises effectively.

Building Delts through Combination Exercises

Other exercises can be performed which also workout all aspects of the deltoids and, thus, help strengthen the entire shoulder. These exercises cause all the muscles to work together as a unit.

One such combination exercise is the diagonal lift which mimics the movement of drawing of a sword from its sheath. While standing, place your right arm across your body and hold a dumbbell against your left hip. Raise your arm up and across your body until your hand is above the right side of your head. Keep your elbow slightly bent. Return to the starting position, repeat for a full set and switch arms.

Other top combination exercises which you can do to benefit the full group of deltoids are push presses and arm circles.