There are two basic types of putts: Long ones, which you want to get close enough for an easy tap-in; and short ones, 10 feet and less, which you want to hole.
It makes sense, then, that there should be two basic types of putting strokes: The long, flowing stroke is well-suited to long putts when distance is important; the short "pop" stroke works best for short putts, when you have to keep the ball on line.
The Long Stroke

The long stroke is just that: Long and
flowing, with a slow, easy tempo.
Take a wide stance and stand a little taller to get a better view of the line. Grip lightly and swing with the arms and shoulders. Keep the wrists quiet, the head and body still. Feel the putterhead swing like a pendulum. Don't worry as much about direction as you do about making solid contact and putting a good roll on the ball.
The Short Stroke

The short stroke is more precise, so you
should start in a controlled, compact position: Bend a
little more at the waist and bring your feet closer
together (but not so close that you lose balance).
Now you can use the small muscles of the wrists and hands. Let them hinge, combining their movement with a little arm and shoulder motion.
It's crucial that the short putt start on line. Pick out a spot a few inches ahead of the ball and concentrate on stroking the ball directly over it.
Private Lessons 1999 Times Mirror Magazines, Inc., used under license by GolfServ Online, Inc. Instructional information provided by Golf Magazine.