Hey I am in the same situation....

For setting, have them set the ball into a basketball hoop. Start nearly under the hoop then slowly move them further away.

Same thing for bump passing, pass the ball into the basket.

Make a game of these two by assigning points for hitting the backboard, for hitting the rim, and the most for getting a basket.

Another one for passing is put a hula hoop or some other large ring on the floor and have them try to pass the ball to get inside the ring.

For serving, have the coaches stand on the other side of the net and give them points for hitting the coach with the ball.

A great and fun serving activity is Dead Fish. This game is played by each person serving the ball and wherever the ball hits the ground on the other side, is where they go and lay.When it is the next persons turn they try to hit the person that is laying on the other side by serving. If the person laying down gets hit, they have to get up and go to the back of the line to serve again. Whoever is the last one standing has to do something funny or embarrasing in front of the whole team!

This is a fun game that will improve their aiming skills and it will appeal to any player.