The shoulder joint is design to allow for maximal movement, however this makes it vulnerable to dislocation. And once it has popped out of joint, it is 50% likely to again.
To prevent shoulder dislocation, it is important to strengthen the 4 muscles which maintain shoulder stability; the Rotator Cuff muscles. Their main role is to work together to hold the humeral head (ball) in the shoulder socket.
Exercises using a resistance band can be very effective in strengthening the Rotator Cuff, these can be done at the gym (cable tower) or at home (1meter loop of resistance band attached to door knob).
Shoulder internal & external rotation as well as abduction exercises should be completed with each arm, 10-15 reps, 3-5 times per day.
If you have sustained a shoulder dislocation in the past; taping or bracing can assist to prevent it happening again. Stretching before 'at risk' sports can be beneficial. And we can always assess the quality and strength of scapula movement and muscles, and provide exercises targeted at any specific instabilities that may have occurred.