On an episode of Mythbusters that I saw a while back they showed the picture of one of the inmates of Alcatraz. I remembered how striking the images looked to me and I went looking again tonight and found a picture of a young man. Here is how it went:
Looking back it is interesting how much more I got into character as the shots progressed. These are in chronological order and the first few are of me just sitting in front of the camera, but by the last two there is a character that has developed.
Note: Give your subjects a prop, it helps!