Drills for volleyball serve?

My team plays a game called beat cartch. for every serve you get over, its a point, and for every serve you miss, cartch gets a point. We generally play to 25. We also play paint the floor where someone lays on the floor on the other side of the net. You have to hit the person on the other side and then you go and join them until all the people on your side are on the other side of the net on the ground.