One of the most common problems I see, even with experienced public speakers, is that they do not seem to be capable of standing still when they should. It is very distracting to try to listen to a public speaking presentation when someone is wandering and swaying around on stage.
I have stated in previous articles that you should move at least three steps, in a particular direction, and for a purpose whenever you move on stage. Small to and fro movements during your speaking engagement are very distracting. As we move into a century that will likely include more distance / TV training, keeping still is even more critical when you are speaking in public.
When you are on TV or video your movements are magnified. I got a good reminder lesson in keeping still while doing the weather and traffic report for a broadcast station in Orlando, Florida. I was all set to be my highly animated self. They put me at an anchor desk and turned me loose with a set script on the teleprompter. My normal performance looked absolutely ridiculous. In fact, it wasn't even close to being acceptable for the tight shot they used. I had to stay perfectly still with the exception of my head and eye movement and facial expressions.
You can practice this at home with a simple video camera zoomed in to a tight close up shot. Either stand or sit and don't move your shoulders and arms at all. Talk to the camera and only allow movement from the neck up. To do an el cheapo simulation of a teleprompter, cellophane tape a script on to the bottom of the lens of the camcorder.
Once you master this technique and can convey all your non-verbal information with only head and eye movement and facial expression, you can add small amounts of body, arm and shoulder movement as the video shot gets wider.