(This is today's bit of advice from the book Safety Toolbox.)
These exercises introduce the concept of grazing a target ball so thin that it barely moves. The closest offensive shooting example would be a very thin (85 to 89 degree angle) cut to pocket an object ball.
That skill should be fine-tuned even more. The goal is to shoot the cue ball against the target object ball and barely move it. The lesser the object ball moves, the greater your mastery. For most purposes, a roll of one inch (2-3 cm) could be considered successful. Lesser movements on purpose would indicate greater mastery. Total control would be to make the target ball shiver in place - not even roll.
The purpose of this shot is two-fold. The first is to keep the target ball very close to its starting position. There can be various game situations why this would be ideal. The second is to apply appropriate spin to the cue ball and send it somewhere with almost no loss from transferred energy.
When the balls are within a half diamond distance of each other, it is much easier to scrape the paint. When more than one diamond apart, it is difficult to properly aim with side spin. Use these exercises to become more precise.
Scrape the paint, example 1
Start with the cue ball a ball width apart. As you learn, move the cue ball further and further away. For this, use 12:00. Keep control of speed.
Scrape the paint, example 2
Use different right side spins as needed. Practice using 12:30, 1:00, 1:30, 2:00, 2:30 and 3:00. Make the results predicable.
Scrape the paint, example 3
Use different left side spins as needed. Practice using 11:30, 11:00, 10:30, 10:00, 9:30, and 9:00. Make the results predictable.
Long table, exercise 1
Use different right side spins as needed. Practice using 12:30, 1:00, 1:30, 2:00, 2:30 and 3:00. Make the results predicable. Use speed control.
Long table, exercise 2
Use different left side spins as needed. Practice using 11:30, 11:00, 10:30, 10:00, 9:30, and 9:00. Make the results predictable. Use speed control.