The drills you want to work on are dependent where you are in your pool career learning curve.
For example, an absolute beginner would be quite happy with scattering some balls on a table, placing the cue ball to line up a simple shot to pocket it, then repeating until all balls are off the table. Goal - get some experience making balls go into the pockets.
An improved players can use the same ball in hand drill, with a goal of sending the cue ball to designated parts of the table, for example a nearby sheet of paper.
A better player would adjust angles, practice various degrees of follow, draw, and side spin.
You know what you need to work on - at the last match you played, you found yourself having the same problem over and over. What ever that problem was, set up that shot and solve it.
And, just practice until your attention starts to wander, then move to something else.
That's the Intelligent Shooter's approach to drills.