Throw my hat, curse, grind my teeth and make my caddy miserable...seriously I just slow it all down, take a deep breath and start with all the basics...I heard that Fred Couples slowly outlines a tree on the course with his eyes from top to bottom when he feels like he is shaken...a form of meditation I suppose but I have tried it and it works to a degree...if you develop checkpoints in your swing you can use those with a few practice swings to feel the groove again...