Stand and hold a small object in one hand, for example a ball.
Draw a large circle with one hand, lifting the hand up in front of you and taking it over your shoulder to bring it down behind you. Follow your hand with your eyes. Repeat using the other arm.
If you wish to make the exercise more challenging, try standing with your feet closer together, toes of one foot beside and touching the side of the heel of the other foot, or feet in line with toes of one foot behind and touching the heel of the other foot.
This exercise focuses on improving your balance. In addition, performing a large circle with your arm improves your shoulder mobility.