How to do it: Use a compound movement such as the Barbell Military Press. Progressively increase the amount of weight you lift.
A fairly good set and rep scheme would be 6 sets of 3. Once you manage to hit all 6 sets of 3, increase the weight and repeat.
Increase Metabolic Stress with a Superset of Compound Movement and Isolation
Another key factor for muscle growth is metabolic stress. Metabolic stress is caused by the buildup of a variety of metabolites such as lactate, hydrogen ions and creatine.
One way to tell if metabolic stress is happening is to create a "pump" in your muscle. The pump is basically caused by fluids building up in the cells and the accumulation of metabolic by-products. Also, more metabolic stress can be created during the lowering portion of a lift, which is why doing isolation exercises is useful.
How to do it: Pair a compound movement (e.g., Arnold Press) and perform it for 8-10 reps, followed by an isolation movement (e.g., Lateral Raises) for 8-10 reps, with emphasis on the lowering portion.
Perform a Shoulder Isolation Exercise 4-5 Times a Week to Increase Frequency
An increase in exercise frequency can further promote muscular hypertrophy. But don't get carried away. Performing Overhead Presses every other day might cause you to have banged-up shoulders.
Opt instead for an isolation movement and perform 3 sets of 10-12 reps 3-5 times a week to increase frequency and total volume. The Lateral Raise fits the bill perfectly because it's joint-friendly. Start with 3 times a week and slowly increase to 5 as you progress.
How to do it: Perform 3 sets of 10-12 reps of Lateral Raises 3-5 times a week.
The Shoulder Workout
1. Barbell Military Press
Sets/Reps: 6x3
2a. Dumbbell Arnold Press
Sets/Reps: 3x8-10
2b. Lateral Raises
Sets/Reps: 3x8-10
( 3 to 5 times a week)