Stand up straight with an agility ladder laid on the floor in front of you.
Starting at one end of the ladder, jump both feet forwards to land in the middle of the first square.
Jump both feet apart, to land outside the ladder, in line with the next square.
Jump both feet back together, and then jump forwards into the 3rd square.
Repeat this sequence.
Try to remain light on the balls of your feet, increasing the speed at which you perform the movement.