Regardless of your approach as a lifter, balanced shoulder development is important. That means both sides are equal in size, shape, proportion, and strength.
When you're lifting barbells or using machines for shoulders, it's natural for your body to rely on its stronger side to do more work to achieve the required reps. The strong side compensates for the weaker one. Unfortunately, those weaker muscles stay weak because they're not forced to handle their share of the load.
This shoulder workout helps remedy that issue. Each exercise calls for you to work the two shoulders independently. The reps are also performed in different ways so there is less chance that the body can adapt. This also keeps the workout interesting and maximizes results.
Give this workout a 6-8-week run, and you should see improvement in balance, shape, size, and strength.
Alternating Arnold Press
The Arnold press is an effective exercise that primarily targets the front deltoids, but also involves the other two heads of the muscle. Use this both as a warm-up exercise and a strength builder by going progressively heavier with each succeeding set.
Start with the weaker of your shoulders. Perform a rep with that side before performing your next rep on the other side. Continue alternating sides until you've performed the required number of reps for both shoulders. Rest 90 seconds between sets.
Single Cable Rear Delt Fly
The rear delts can be difficult to engage, but this movement should help with that engagement. The cable helps you keep tension on the muscle throughout the exercise, and the motion is restricted so you can concentrate on really isolating your rear delts.
Keep a slight bend in your elbow and pull back as far as you can. Once you feel that contraction at its fullest, hold it briefly before lowering the weight. Perform all the reps on one side before switching. Rest 60 seconds after you've completed both sides.
Single-Arm Seated Lateral Raise
You're going to need to go light on this exercise, but it will be worth it. Several pro tips can add difficulty and help you get more out of each set.
First, being seated limits the amount of momentum you can use. This enables you to focus on the side delts instead of on simply lifting weight.
You're also going to hold one side up at the top, in an isometric contraction, while performing reps with the other side. To do this, sit on a bench with weights in both hands. Hold one arm straight out to your side at shoulder height while you perform five lateral raises with the other arm. Once you complete the fifth rep, hold that side at the top and do 5 reps on the other side.
Repeat this pattern one more time for both sides. That extra burn you feel is a sure sign your side delts are working overtime. Rest 60 seconds between sets.