Have you ever noticed how buff professional rowers are? It's no surprise, given that they practice 70% of the day and compete any time they're not practicing, but the secret to their majorly built and sexy upper body is the simple yet effective motion of rowing.
Moving your arms forward works your biceps, while pulling them back works your triceps. To get the arm and shoulder toning benefits of rowing without needing to actually be out on the water, simply take a gander at this video to learn how to do an upright row.
When you work shoulders you have to hit them with two different types of exercises. You must do both press type and pull (or lateral) type movements.