Not sure what kind of drill you are looking for but if you are looking to refine your stroke this is my go to. Learned it from that full length instructional video on YouTube (I forget the name... Maybe billiard x or something).
One after another put a ball on the spot and go through your whole preshot routine shooting said ball directly into one of the far corner pockets. Make sure that your tip stops on the cloth whether you are striking the top, middle, or bottom of the cueball. Don't put the tip on the cloth after your stroke has finished... It needs to naturally land there at the end of the stroke. Once the stroke is done remain in your finished position for 3 seconds. Repeat for a couple racks worth of balls. Technically you are supposed to do this drill several hundred times before shooting a normal game as it basically reworks your whole stroke.
I always go back to this drill whenever I develop a weird hitch in my stroke. It's simple but very effective in developing the muscle memory required so that in a match your mind stops getting in the way.
I like to shoot for different parts of the pocket and not just concentrate on hitting center pocket every time.
