It depends largely on when, where, and to whom I am speaking.
The less I can say to make my point, the better. My head tends to stay still, my gaze will focus down or to the side rather than on the face of who I am speaking to so that I can focus on collecting my thoughts and articulating them in an accurate and precise manner. While my head will not move much, my hands will often gesture to articulate concepts or objects to which I am referring, as though I were drawing an illustration or diagram in front of me to better illustrate my words.
I don't like being made to repeat myself, although I am happy to rearticulate at times.
I've been told my voice is monotone at times. However, if I get really excited about something, I can speak miles a minute and my voice can become much more animated, "alive"