How can I look less scared during public speaking?

-So my face LOOKS really scared, and I feel myself trembling! Please help for I really, really want to get in the debates team next year.

I guess I can practice in front of the mirror but on what topics?



Thanks for your help!my cousin's wife told me when you put your tongue on the roof of your mouth no one can tell how you really feel because you don't give anything away, but you can't speak like that so practicing in front of a mirror is a great idea. practice using topics like how do you feel about the economy and what can we do to make it better or what do you think we can do to reverse the effects of global warming.