drills
the best drill i have done is a simple black/red drill. With the black on its spot, stagger 8 reds above it, kind of like a ladder, pot the red, black, and get shape on the next red to get the correct angle on the black. This develops a ton of touch and feel for the important scoring opportunities.
Ive worked with Tom Kollins quite a bit, and he uses this drill to focus his touch in.