Heard this idea posted before but seen it being used this weekend at a tourney.I'm more of a visual kind of person.What this team had was a clip(I seen them on the ends of dog leashes)not sure what it is called.Clipped one end to the chain link fence.They used a plastic coated rope I believed about 10 feet long or longer.Threaded through the rope was 12 yellow softball wiffle balls.The other end of the rope they had a plastic handle made out of PVC which they attach the rope too. One end clipped to fence the other handle end held by coach.Each girl stepped up to bat slide 1 ball up aways took her batting stance and took a swing.Instant feed back if the ball was hit correctly.If the ball slide to or near the end good swing if the rope or ball bounced up and down or hardly moved not so good of a swing.I will be making one of these.