Making a circle with the ball of your foot.
While standing with a straight back, put the right leg behind you and your right foot back on your toes, pressing them into the floor while bringing your right heel up at the same time. The arch of the foot will be contracted now. Perform a full circle with your foot. Go in both directions. Alternate legs.
This exercise brings a lot of blood flow and energy into the feet, will improve flexibility and help you maintain balance.