I got the inspiration for this coaching tip from Julie, a fastpitch [tag]softball[/tag] coach for a group of 13 year olds. It includes some fresh ideas on [tag]fastpitch softball practice drills[/tag]. Try it out and let me know what you think! 
Lateral Shuffle
Start: Stand to one side of the ladder, with the hips and shoulders perpendicular to the ladder. Get in an athletic position. The lead foot will be the one closest to the ladder.
Action: Place the lead foot inside the first square. Next bring the trail foot into the first square, while at the same time laterally moving the lead foot to the outside of the first square. Take the trail foot that is in the first square and move it forward to the second square. Bring the outside (lead) foot into the second square, while moving the inside (trail) foot to the starting side of the ladder. Continue to shuffle laterally through each square of the ladder.
Focus points: Stay low by bending your knees and keeping your hips low. Move quickly, staying on the balls of the feet.