When you watch your favorite Tour player putt on TV, you're probably focused on the outcome—will he make it or miss it? Next time, pay attention to his stroke. You'll notice that he—and most of his competitors—swings the putter back on the count of "one" and through on the count of "two."
And he putts with the same one-two tempo every time, whether it's a 40-foot uphill lag or a three-footer to save par. Sure, his stroke gets longer on lengthy putts and shorter on tap-ins, but the one-two count is always there.
The pro way to putt is much different from the way high-handicaps do it. Poor putters tend to use the same stroke length for all putts, hitting short ones easier and long ones harder with a slower or faster stroke, respectively. Changing how hard you hit putts leads to inconsistent strikes and explains why you often follow a putt that falls short with one that runs five feet past.
To see how stroke length properly differs depending on distance, notice how I adjust the length of my back-and-through stroke on putts of 3, 12 and 36 feet.
On the 3-footer (top image), I swing the putter back just a few inches behind the ball and stop my forward-stroke about the same length in front of the ball. I swing toe-to-toe on the 12-foot putt (middle), and make a much longer stroke for the 36-footer (bottom).
The common denominator is that each stroke is made with the same one-two tempo and takes the same amount of time to complete. Even as my stroke gets longer on the 12- and 36-foot putts, I keep my wrists and body from adding extra power. I just swing in time with the one-two beat.
If it looks and sounds simple, it's because it is simple. When you're on the green, make a practice stroke using a one-two rhythm. If you feel that this stroke won't get the ball to the hole, make a longer practice stroke but with the same rhythm (or make a smaller stroke if your first practice move feels like it would blast the ball too far past the cup).
Once you feel that your stroke length is a match for the putt at hand, step in and go. I guarantee that if you stick with this method, you'll roll the ball the correct distance a high percentage of the time.