Ok, so we can't start to build up the muscles in your shoulders without knowing what muscles make up your shoulders. The shoulder is made up of two groups: extrinsic muscles, which originate from the torso, and attach to the bones of the shoulder, and intrinsic muscles, which originate from the scapula and/or clavicle, and attach to the humerus. With so many muscles to work, no one exercise will work them all, so we've put together a list of exercises that target different shoulder muscles. ~ Berceste