Theres 1 that really helps, the drop drop lift lift drill. Not sure if thats clear. You might already know it, first person serves high, opponent drops, server drops back, opponent lifts, server clears, opponent drops, on so on.......
the clear, smash, drop drill if fun ! heres how it works Person#1 (serves) - Clears Person#2 - Smashes Person#1 - Drops it to net Person#2 - Lifts it at net Person#1 - Smashes Person#2 - Drops it to net Person#1 - Lifts it at net Person#2 - Smashes etc. i also like Clearing only drills .. where one person hits down the line clears and the other cross court or both hit cross court and theres footwork drills which you can do on your own