Most putting experts agree that one of the top 3 imperatives in putting is to have a square putter face at impact. Most amateurs rotate the putter during the stroke, and are either too open or closed at impact. This results in a “side swipe” stroke, the net result is improper direction and distance control.
How do you work on putter face?
There are many high tech, expensive gadgets on the market to help with this, lasers, etc. The simple “magic” solution is found in your home: a magic marker!
Make sure the end of the marker has a flat surface (i.e. you can stand it up on a counter top). Place the marker on a smooth floor surface (carpet does not work well) and “putt” the flat end of the magic marker. If the marker spins to the right (clockwise), then you know your putter face was “closed”. If the marker spins to the left (counter-clockwise) then you know your putter face was “open”.
Keep practicing until you no longer spin the magic marker!