What are good basic and fun drills to do with beginner/improvers?

What are good basic and fun drills to do with beginner/improvers in large groups (20-25)?

I have a whole range of drills/games called rally concepts, these can be set up on a number of courts and are suitable for beginners to work on their own and coach to circulate. Players then change courts so they all get a chance at the different concepts. Go to%3A [link removed]

Apologies for the lack of detail but this is due to the need to show these on a drawn court - I will however explain a couple of these fun concepts. 1/. Chinese take-away. Place groups of chinese hat (say 8 or 9) in a group each side of the net - distance from net depending on skill level - they can be placed to encourage back hands and F/H. players rally trying to hit the hats - if they hit one this is taken to their side of the net. 2/. Hot Potato - two cones are placed on each side of the net - one on the singles side line the other on the centre line - one has a ball on the top. These cones can be placed in different positions to increase difficulty. Players rally (say 3 hits) and pick the ball up - rally another 2 hits and place the ball on the opposite cone. 3/. Energy gates. Two cones are placed each side of the net (lets say to begin these are placed on the service line) Players rally a number of hits - decided by the pro - and then have to go back through the cones to regain their energy, but keeping the rally going. The jkids love these concepts and they can be set up on half a court and they move round the circuit doing a different one each time. I have a lot of these and so it will be appreciated why I suggested viewing them elsewhere.