STARTING POSITION:
Select the appropriate weight of the dumbbells. Stand straight with a dumbbell in each hand on either side of your hips. You should use a neutral grip. Retract your shoulder blade and bend your elbows around 90º. Now do an external rotation of your shoulders so the hands are separating from each other but the elbows are close to the body.
MOVEMENT:
Without moving the elbows, lift the weights just above your head in a semicircular motion while you exhale. Return to the starting position with a smooth movement while you inhale.
TIPS: While your are doing the exercise, move only the arms, make sure you don't move any other part of your body. The exercise key is quality over quantity. The trick is to perform the exercise using proper form. Make sure your shoulder blades are always retracted.