I use it for my daughter's training. (She is a D1 player and we live in a weak area for tennis.) Here's a few things we do:
1. Volley technique. Machine near service line, soft pace, fast feed rate, slight backspin, set to sweep. Focus on footwork, placement, technique.
2. Volley attack. Machine set at baseline, fast pace, fast feed, flat ball, sweep off, volley three consecutive balls approaching from no-man's land to closing on top of net. Alternate forehand/backhand for footwork.
3. Baseline grinders. Machine at baseline hash mark, set to sweep, feed rate set to shoot just as player's return reaches baseline. Hit 20 balls in a row to targets. For variety, increase speed or set spin to heavy top or slice. Focus on consistency, precision.
4. Attack shots. Machine behind baseline, pace medium, set slightly high/topspin ball to midcourt or slightly deeper. Practice attacking shots to targets for BH then FH. Or set to sweep and work in increments.
5. Overhead practice. I find I don't need to use the height extension under the machine. Set machine 10-15 feet behind baseline, flat or backspin, slow pace, slow feed rate, have player begin from net position to retreat for lob behind service line. For agility, set to sweep.
Like some others on the forum, I set the machine on two Husky X-carts for service return practice. Once in a while we will use the machine to practice drop shots and lobs as well. You're limited only by your imagination. We use the machine for probably one-third of her tennis workouts (but we don't have many workout partners).