Smile as often as you can. Cameras tend to turn perfectly personable presenters into robots. Watch yourself in the mirror to rehearse or practice with a home video camera. Ask for a recording of the program to critique yourself. Slow your movements slightly for the camera.
Speed seems exaggerated when viewed on a television monitor.
If demonstrating or holding an object for the camera, hold it still and turn it slowly. Watch for reflections from lights. Excise nervous habits from your soul. Finger tapping, head scratching, ear pulling, weight shifting, eye blinking and other nervous twitches will drive the viewing audience crazy. If alone with the camera, maintain comfortable eye contact with the audience on the other side of the lens.