Line up the mirror to the cup, and line up yourself to the mirror. You are READY!
Create a putter gate with a tee just off the toe and heel of the putter. This assures a proper stroke path, and sweet-spot hit.
Sword Drill – Keep the putter face square at impact.
If you can roll the ball down the Sword, the face is square at impact, and the putter is moving through impact. These are the most likely faults of missing short putts.