This drill is best done with pairs of players. Draw a "back line" halfway between the service line and the baseline and a "front line" halfway between the service line and net. Start with one player centered on the right half of the back line; the other on the left. The player on the right runs forward and tags the front line with her foot, at which point you lob so that she'll have to scoot back at least several feet to reach your lob with a smash. The other player is entirely safe from being hit by the smash, because she's farther back than the smasher. As soon as the smasher has hit, she retreats to the back line, and the other player runs forward, tags up, and scoots back for her own smash. The two alternate like this until each has hit a set number of smashes, usually 6-10. Once you get the right timing and depth for the feeds, the players will feel as if they're in almost constant motion, and it's quite a lively drill.
Although the depths specified above for the two lines result in the most realistic scoot smashes, you can move both lines forward to make the drill easier. For first-timers, the service line makes a good back line, from which the players run forward to tag the net (with their racquets).
Difficulties: Lobbing at the right height and depth to give the smasher a challenging scoot takes practice, and scooting ability varies quite a bit from one player to the next. Make sure that the players always clear any balls that they've hit into the net, and keep any waiting pairs safely farther back than the smashers.
