The Scottish Chick, Yes, thanks for sharing this video. I just did a presentation last week, and I wish I had watched that first! On the positive side, I already felt more confident based on some of my body language learnings. So trust that you already have tools to help you.
Otherwise, I find practicing beforehand really helpful. I practice by myself, while imagining I'm in the environment. If you have the time (and courage), practicing with a friend or small group of friends is also super helpful!
Have fun, and keep us posted!