One of the most valuable things that has happened to me regarding public speaking was watching a talk that I gave. I said 'um' way more than I perceived I did. It was painful to watch. I now do everything in my power not to utter it. Instead, I simply pause. My talks have much improved as a result. If I were to become a politician, I would watch my own speeches whenever possible. IMO another important thing to do is to tell a story. It is so much easier to talk about something when you frame it in the context of a story. I get a bit nervous before a talk, but I've learned to prepare a bit more, and to care a lot less. The audience mostly just wants to relax and learn about something. If you do your best to explain something without boring them, you'll be alright. In a couple of weeks, I am slated to give a talk to the Physics Department of my alma mater. As a student, I used to attend these talks religiously. It will be interesting to be on the other side of the podium, and to present to the faculty that taught me.
Watching your talks, what a great piece of advice mk. Was there anything beyond the "um's" that you noticed while watching it? Did it change how you perceive your mannerisms when talking? I find that I'm more engaged when someone effectively uses hand gestures/body language when speaking. It tends to show me that they're more engaged. I like the idea of communicating ideas through stories. When making presentations, I will often try to use stories or metaphor to communicate a complex idea, to make something that seemed undesirable seem attainable and attractive. This has taken years to get good at. I will also try to challenge assumptions, nothing gets your audience captivated like being challenged. Good luck with your talk, it sounds like a cool moment in your professional development. The student has become the master! Try not to laugh uncontrollably ;-)