Crossing the Line

One of the most common problems in golf is aiming one way and swinging another. The result is always a glancing blow to the ball rather than a solid compressed shot.
You must first learn how to hit the ball straight before you can aim correctly. You need a straight line target to do this. Place a club on the ground to indicate the target direction and then align your body parallel to it. Your goal is to swing the club on the inside of the target line. Do this slowly to start so that you can watch the club travel and then gradually speed it up.
You can graduate to hitting balls with a training wheel (3 foot 2X4 of soft pine).  Place the ball just inside of the board and see if you can avoid getting splinters.