It’s a good idea to have a solid tantrum before you try a whirlybird, meaning one in which you land wake-to-wake every time. The whirlybird requires two things that are different from a tantrum, though. First, as you come off the top of the wake, throw your back shoulder a little harder toward the shore to which you are headed. Second, throw your head hard across your back shoulder; this will help you complete the 360 rotation in the air and spot the landing. Spot it just like a tantrum and come down with your knees soft.
Keep your elbow in to your body so that your arm is bent upon takeoff. You want the handle to be close to your ear when you initiate the “whirly” part of the move.