Create a pre shot routine in three phases, one where you visualize, one where you align and one where you pick a key to initiate the swing
Heel shots are caused because you either move the center of your plane out towards the ball during your swing or you start too close to the ball at address
Belly putters are a great option for those players having a hard time making an arc with their putting stroke or have a hard time keeping the clubface square because they anchor the putter handle on the torso