There's a drill that Colin Colenso suggests and which has helped me to shoot better overall.
Take a striped ball, and shoot it with a soft stroke very low on the ball, you want to shoot a soft draw shot, where the striped ball loses its backward spin at one diamond's distance. Groove this shot and mentally say it's Power 1. It's essentially a drag draw stroke. Perfect for stop shots at a diamond's or a bit more distance. Then do the same thing but find the power and stroke to make the striped ball lose its backspin at the 2 diamond distance. Groove this stroke and speed too. Mentally make this a Power 2 stroke. Then do the same for the 3 diamond distance, and the 4 diamond distance. Power levels 3 and 4 respectively. This stroke may well become a staple in his repertoire. It's useful not only for stop shots, but also for drag draw shots at many distances, and mastering it will result in more balls potting. By the way, shooting this shot on a ball at a diamond away with a Power 2 stroke will definitely draw the cue ball, and more than you might expect, depending on how fast the table is, and with minimal effort.
Good luck!
Flex
Take a striped ball, and shoot it with a soft stroke very low on the ball, you want to shoot a soft draw shot, where the striped ball loses its backward spin at one diamond's distance. Groove this shot and mentally say it's Power 1. It's essentially a drag draw stroke. Perfect for stop shots at a diamond's or a bit more distance. Then do the same thing but find the power and stroke to make the striped ball lose its backspin at the 2 diamond distance. Groove this stroke and speed too. Mentally make this a Power 2 stroke. Then do the same for the 3 diamond distance, and the 4 diamond distance. Power levels 3 and 4 respectively. This stroke may well become a staple in his repertoire. It's useful not only for stop shots, but also for drag draw shots at many distances, and mastering it will result in more balls potting. By the way, shooting this shot on a ball at a diamond away with a Power 2 stroke will definitely draw the cue ball, and more than you might expect, depending on how fast the table is, and with minimal effort.
Good luck!
Flex