unasked for advice: get on a putting green and find a straight putt. use the line on the ball and from behind the ball, line it up at the hole. address the ball square to the line and don't get caught up in how the hole looks in your address position. hit the putt and keep your head down, don't watch it. keep doing that until you can stroke it straight into the cup. practice those from about 4 feet and that goes a long way. use that line for all putts (it matters less on the long lag ones) but you'll find you're getting more on line.

Once you can hit it on line, you can set the line for your putt and then when you're standing over it, just think about speed and hit the putt and trust that line you choose from behind the ball.