THIS STORY IS FOR YOU IF...
1. Your putts never travel on the line you intended.
2. You think marking your ball with a line will help.
A lot of players these days, including some very notable PGA Tour players, have taken to marking their golf balls with different types of alignment aids. The most common is a straight line drawn down the seam of the ball (see photo), which is then aimed down the target line. There are other alignment techniques, but I don't condone any of them. Focusing on a drawn line or a side stamp only distracts you from the real target line.
Forget marker lines and use the best aiming tool you've gotyour eyes. Not only to identify your line, but to draw that line from start to finish. You should feel as though your eye line is a track that your putter must follow. To ingrain this feeling, assume your address position with your putter soled directly under your peepers, then imagine a track and practice moving your putter back and forth without straying from it. Once you feel comfortable, place a ball down and try to re-create the same image and feel. Not only will this technique help you develop a more solid stroke, it should also alleviate a lot of tension and improve your distance control.