Though normally thought of as a toy for children, attached ball paddleballs are a great tool for sharpening your hand eye coordination and getting comfortable with the paddle.
Hold the paddle in your dominant hand with your wrist facing up.
Flick your wrist upward to maneuver the ball to rest on top of the paddle.
Continue flicking your wrist to bounce the ball off the top of the paddle. Your goal is to continuously be able to bounce the ball on the paddle without the ball falling.