The “back to front” drill is an absolute must in your drill and practice sessions. It’s where you or your partner, whoever is the initiator, notices that the other person on the other side of the court is starting off short.
You should be trying to hit the ball at your partners shoelaces while they are keeping their body forward, with their shoulders, knees, and hips all facing forward. You never want to hit low from your side in a defensive ball because then you’re out of position in case that ball pops back up. You want to be in an open stance.
In this drill, your partner is going to hit two balls, take a step back, two more balls, and take a step back, all the way to the baseline. Then repeat the drill with them moving forward. You do this until they miss. The hope is that they get back to the baseline and back to the kitchen line about three or four times without a miss. Your pace on the ball should be about a 50% pace. As your partner improves, you can get harder and harder with your pace.