First, learn how to fix your look. When you shoot, you want to look anywhere, just not to the camera. There is a simple exercise: stick a coin or a small black mark on the wall at eye level. Imagine that this is a lens and work looking at this coin. Being able to make eye contact is very important. This will depend on people believe you or not.
Sometimes, the actor looks at the camera, but the view is absent. And like the text reads well, but something, there is no spark, heat. In order to remedy the situation, imagine a loved one on the other side of the camera, someone who treats you well and your eyes become softer and it will fire. Look deeply. Your target is not to get into the eyes, but into the soul. It's an acting technique, also play love in the look. Just don't overdo, you can get a monologue of the cat in March. It makes no sense to write that you need to know the text, it is so clear. But it happens that the actor or TV-host knows the text, but is afraid to forget it. And this fear to forget the text is always very noticeable to the audience; it fetters the person in front of the camera. Your target is to clearly understand what you are talking about, if that improvise, speak in your own words. If this is the hero's monologue, you must live it here and now. Include your emotions to the fullest! Mechanical retelling of the memorized text will make a doll from you.
If you telling the camera about yourself, for example, during the casting, try not to make long pauses and don't use filler-words. Always winning looks witty story, try to amuse the audience with funny language or unusual examples from life. You must be extraordinary person; boredom is your main enemy!
And the last, smile with your eyes! A smile is the key to the camera loving you. And your laughter, it has so much to say about you. Listen to your laughter and work on it, there is always something to improve in yourself.