The latest question I have been asked is to demonstrate a drill which will help you to hole more short putts on sloping greens.
Start by placing 12 tees in the ground one putter length from the hole, as pictured right.
Then try and putt a ball from each of the tees without missing any.
If you do then you have to start again.
If you hole all 12 balls in a row then move the tees back the length of your grip.
Again try and hole all 12 in a row.
If you miss then start again. Keep practicing this drill and every time you complete the 12, move the tees back another grip length.
This is going to help you gain a better feel for the varying slopes and speeds you will be faced with when putting on the course.