Dumbbell Side External Rotator Raises - Lie on your side on a bench with the "up" elbow against your side so that your upper arm is parallel to the floor and the forearm hanging down in front of your body (dumbbell in hand, knuckles out).
Anyone who uses the shoulder for repetitive actions such as swinging a tennis racket, throwing a ball or even lifting a weight may be prone to rotator cuff tears, which is a tearing of the tendons in the rotator cuff.
If you're doing it right and still feel pain, it may be time to check in with a professional; some injuries feel very similar to weakened rotator cuffs, but may require more thorough treatment.
Cable Internal Rotator Pulls - This exercise is the same as the external pulls above, except you pull so that the handle rotates in towards your belly, similar to the movement of arm wrestling.
Rolling over in bed: This may sound odd; but if the shoulder area is unstable, even the slightest movement in the wrong direction can cause a rotator cuff injury.