Don’t try to act for the camera, just be your natural self and speak from the heart. It doesn’t matter if you fumble nor does it matter if your idiosyncrasies come across, this all will add to the organic nature of the video.
You Are The Writer:
What you say on camera is what comes from within you. Write down a few notes, bullet points or even entire lines if it helps you to remember. You are the writer and this is your emotional expression.
Practice Makes Perfect:
Practice what you would like to say in front of a mirror a few times. Get comfortable with yourself and speaking out your thoughts.
Make sure you seat yourself comfortably, make sure your environment is comfortable from you. And once the camera rolls, forget that it is there and just talk as you would to another person.
Try, Try Again:
Shoot as many times as you need and as many takes as you need to get comfortable with the lens.