Reading greens correctly is the key to holing good putts. You can hit the best putt in the world, but if it is on the wrong line, it won't go in the hole. Much like you shouldn't get in your car without knowing how to get to where you are going, you shouldn't step up to a putt until you know how to get it to the hole.
In this video, Justin Rose explains how he deals with breaking putts and shares a drill that could improve your performance on the greens.
Moving The Centre Of The Hole
Justin explains how the centre of the hole actually moves depending on the break of the putt. If a putt breaks severely from the right, the effective centre of the hole may be 4 o'clock rather than 6 o'clock, if the hole were a clock face. Understanding this and using that idea to better visualise the line of a putt can drastically improve your success on breaking putts.
You can use a tee to help you on these putts in a couple of different ways. Either place a tee in the ground in the middle of the hole as you look at it, and then try and make the putt drop in, around the tee, from the high side of the cup. Alternatively, as Justin does, place a tee inside the hole highlighting the effective centre of the hole based on the break and then try and hole the putt directly over the tee.