Perform dumbbell lateral raises to exercise the oft-neglected shoulder muscles. According to Joe Wuebben, author of "Stronger Arms & Upper Body," lateral dumbbell raises quickly strengthen muscles of the shoulders and upper arms.
To perform a lateral dumbbell raise, hold a dumbbell in either hand with your knees slightly bent. Lean forward, keeping your back straight, until your torso is parallel with the floor. Hold the dumbbells down by your knees with your arms slightly bent. Slowly raise your arms out to the sides as though you are squeezing your shoulder blades together, and hold for one second. Release slowly back to the starting position to complete one repetition.
Perform 10 to 12 repetitions to complete one set, and do three to four sets every two days, says Wuebben.
Perform triceps curls to exercise and strengthen the triceps, the largest muscles in the arm. According to Joe Kita, author of "Men's Health Best Arms," the triceps curl builds muscle mass, making it an effective upper arm exercise.
To perform a triceps curl, stand with your back straight holding a dumbbell in both hands. Raise your hands above your head so that you arms are straight. Slowly bend at your elbows and lower the weight behind your head as far as is comfortable before slowly returning to the starting position.
This completes one triceps curl repetition; perform eight to 10 repetitions to complete one set. To effectively build the triceps muscles, do three to five sets three to four days a week, says Kita.
Perform biceps curls to tone the large muscles across the front of the arm. According to Peter Sisco, author of "Power Factor Specialization: Chest & Arms," the biceps curl produces quick results when paired with the triceps curl.
To perform a biceps curl, stand with your legs and back straight, arms at your sides holding a dumbbell in each hand. Slowly raise the weights up toward your shoulders until they are approximately one inch away. Hold this position for two seconds before slowly releasing to complete one repetition of the biceps curl.
Perform 12 to 16 repetitions for one set, and do two to four sets of biceps curls every two days, writes Sisco.