I've been practicing recently for various speeches and even some phone calls. When I don't have anyone to evaluate me, I have to be my own worst enemy and drag out an audio or video recorder then proceed to evaluate myself.
It's painful. The voice that I think has a somewhat sonorous tone is nasal and high. The smooth and flowing hand gesture is quick and jerky.
Always very educational. The second and third takes are significantly better as a result of review. Try it. You might not like it, but whomsoever listens to you afterwards will.
Not brain surgery, but effective nonetheless.