Coach tosses the ball anywhere on the court (or off the court) and calls out a number between 1-3. Players have that many contacts to get the ball back to Coach.
Preliminary: Play for 3 minutes or so.
Player Focus: Focus on one player and have them return one-contact back to you (shout "1") - short, long, tip, rolls. After ~10 of these, have them assume a defensive position to dig a hard-hit ball. When they dig a playable ball, they are out and you can focus on the next player.
New players fill in to replace when they get out of the drill.
If you do not have a ball in hand, count down from 3. If you reach 0 without a ball, there is a team consequence.
Should be tiring.
New hitters rarely miss because of their arm. They miss because of their feet. Build a reliable approach, then time it with your setter.
When your hitter gets stuffed, five teammates standing and watching is how you lose the point. Good attack coverage turns a blocked ball into a second swing.
Coaches spend hours correcting arms in serve receive when the real fault is almost always the feet. Fix the movement and the platform fixes itself.