Distance and Direction
To putt successfully, you need to roll the ball on the correct path and at the right speed.
Set the clubface square to your target line. That is, the putter face should be pointing down the line on which you want to start your putt.
Your eyes should be over the target line (not below or above it), with the ball in the center or slightly ahead of center in your stance.
Your palms should face each other--regardless of your grip technique. In addition to a standard grip, the reverse overlap and the cross-handed grip are common ways to hold a putter.
Using a pendulum shoulder motion, keep your body still. Make an accelerating stroke along the target line. The follow-through should be at least as long as the takeaway.
With putting, there's always a professional--or amateur--golfer who successfully uses a technique that deviates from the norm. If it works consistently, keep doing it.