Originally Posted by HokiePaul

a little thing, but try not to carry your whistle around in your hand when you are moving to report a foul or go to a spot on the floor (either put it in your mouth or let it hang on the lanyard). It helps you walk more with a purpose and look more credible if both your hands are free.

This was something a clinician pointed out to me last summer that I didn't even realize I was doing -- it was a hard habit to break.