The Box Drill
The concept of this drill couldn’t be simpler: Use four tees to create a square, either surrounding a hole or by itself, then stroke balls from varying distances up to forty or fifty feet away so they stop within the square’s boundaries. Start with a box three feet on each side. Once you’re reliably able to stop eight of ten putts within the box, shorten the sides a bit. Ultimately you should be able to stop balls within a box that’s eighteen inches per side.
What makes this drill so effective is that you can rig it to get the thrill of success no matter what your skill level is. When you practice lag putting to a hole, most of the time you miss, and in my view watching putt after putt miss the hole is not good for the old psychology. Similarly, putting to get the ball close to a single tee in the green doesn’t give you the same kind of clear-cut focus that putting to stop the ball within a box does.