Here's a couple...I think these are from Bert Kinnister.
Place an ob at center table. Place cb adjacent to ob that allows you to shoot unimpeded at the second diamond on the long rail. With some running english, shoot the speed that brings cb around 3 rails to barely contact the ob.
Others: More general:
...spread a few ob's (6-10)along the head line...in sequence, hit each a little further than the last one, without hitting end rail. If it gets too easy...add more balls to the lineup. Then try it, with hitting the end rail, and rebounding progressively further on each shot.
And then...same thing, but with bih, hit each ob with cb, sending ob a little further than the last one. Then as above, bounce ob off end rail, progressively further up table until you hit the cb that's still uptable.
Both of these drills include hitting center ball, trying to have cb, or ob travel straight after hitting the back rail.
......
Real soft....put a ball in the jaws of side pocket..hit softly multiple times until pocketed in opposite side pocket. The more strokes, the better.
Varying bridge distances and short, soft strokes of increasing speed and stroke length are immediate feedback. Haven't tried these with eyes closed, but that could be interesting, but since focusing on cb is helpful, might not work.
For 1P..try 3 railers that die after rubbing a ball on the end rail near opponents pocket..hitting ob on the correct side, or no hit, leaving cb on the correct side.
I'm sure there are other, possibly better drills around. These are challenging enough for me...and they seem to help with muscle memory.
Experiment with grip pressures, stoke length, one stroking, especially moving the ball real short distances..
The finesse part of the game is the hardest for me, and 'touch' drills can get frustrating since they are not our normal tempo and stroke speed.
Have fun.