Your hands or wrists move too much during your putting stroke.
You tend to miss the majority of your long putts on the low side of the hole.
It is windy on the green but not windy where you are standing.
You constantly come up short on all of your long putts.
You have a downhill putt with a large break.
You keep missing your putts to the left and right of the cup and you are using a belly putter.
You are having difficulties aiming while putting.
When you get nervous, your putts become short and quick. This, of course makes you miss the cup.
You tend to decelerate your putts because you realize halfway through the stroke that you are swinging too quickly or using too long of a stroke.
You want to improve the feel in your putting.