One group (court) will be serving, while the other will be doing a setting drill. (10 mins, then switch).
Serving Drill: First five minutes we want to see spin serves (consistency over anything). We don't care if it's a standing or jump serve. The next five will be float serves.
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.