Let that camera become a part of your body and forget it is there.
Have you ever had a great convo with someone where you were both excited about the subject at hand? Pretend that that person is with you, hanging on to your every word, and talk like you have his/hers attention.
It will be bumpy and awkward at first but remember when you are recording that you're the only one there. No one will see your mistakes unless you make a blooper reel.
If you start to say something awkward, dont even stop recording. Just stop yourself, reset your camera position and repeat yourself until you like how it sounds. Doesnt matter if it is 10 times with 5 "f**k!" frustration comments in the middle.
When you go to edit, listen to and watch all of them. Critique yourself personally, take mental notes for next time, and go with the one you're happy with.
The more you do this, the less takes you will have to do, or at least give zero s***s about how you sound, knowing you're gonna get it right eventually.
My personal method and I'm still fairly new. Hope this helps.