Medicine Ball "Alphabet"
This is a great exercise to put your shoulder muscles through a full range of motion. This one can be tough, so start out just by going partially through the alphabet, and then work your way up to the full A through Z.
You'll need a medicine ball for this exercise, but don't worry if you don't have access to one. Use something like a gallon jug that's partially to completely full, or fill a bag with sand and weigh it (say one to four pounds, depending on your shoulder strength).
Start in a "relaxed stance." Take the medicine ball and support it in both hands out in front of your body.
Maintain a slight bend to your elbows throughout this exercise.
Start "drawing" the alphabet one letter at a time. You do this by rotating your arms, from the shoulders only, in the pattern of the specific letter, starting with the letter A. Make nice big, full letters with big motion so that your shoulders get lots of work and a full range of motion.
When you first start doing this exercise, it's best to start with a very light weight (say one or two pounds at the most) to see how your shoulders tolerate this exercise. Your letters should range no higher than your head, and no lower than your waist. All letters are formed out in front of your body. Keep those arms straight, with just a slight bend at the elbows.
As with all exercise programs, always check with your physician and a certified conditioning specialist before undertaking any of these exercises.