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.