The Cuban Press targets the rotator cuff muscles of your shoulders.
Steps
Stand with your feet shoulder-width apart. Grip a dumbbell in each hand with an overhand grip. Bring your elbows up and let your forearms hang down. The weights you're using should be light enough that this doesn't require much effort. Your elbows should be at a 90 degree angle.
From this starting position rotate your shoulders so your forearms go from facing down towards the ground, to facing up towards the ceiling. Next, slowly rotate your shoulders so your forearms point at the ground again.
Tips
As with most rotator cuff exercises, you don't need to use a heavy weight with the cuban press.
Keep your back straight and your abs tight throughout this exercise.