I love it when my students suggest tennis activities. Thanks Will C. for sharing this one. I used it recently in an adult beginner clinic focusing on backhands and loved how it dovetailed with the backhand lesson. It's simple, which I also love. You will need at least two players.
One player is bounce feeding; the other is returning. Feeding player calls out 'forehand' or 'backhand' quickly, before fed ball crosses net. Returning player must hit whatever stroke was just called by feeding player. When we played this we played mini tennis (service line) but it could also work well from the baseline.
Scoring strategies: Will suggested scoring first to 7 points, then switch. If the point continues past the feed, EVERY ball hit must be accompanied by a stroke command (Forehand or Backhand), so the returning player can get in on the fun as well even though they don't get to feed (yet).
When I used this in the adult class, I didn't do it by points earned. Instead I gave every player 5 balls and rotated them around, giving everyone equal opportunities to feed as well as return.
At first this game may seem to be more of a learning opportunity for the returning player, to work on tracking the ball quickly and improving their footwork. It is, but as you play this, you may find it is equally a challenge for the feeding player. You will see their mental wheels spinning as the plot where to feed the ball and what stroke to require from their opponent. It's a win-win!