Avoid tapping, fidgeting, and fumbling writes Carmine Gallo, a communication coach and author of Fire Them Up! He goes on to write that such nervous gestures work against your effort to appear as a confident and competent leader. Your body speaks so loud, people don't hear what you are saying.
Need help getting rid of the nervous gestures? Self-awareness is a great place to start. Enlist mentors or peers to give you honest feedback about your annoying habits. Also make an effort to video tape yourself during meetings, speeches, etc and view with a coach. These are just a few thoughts---remember every great performer has a coach.