Here is a nice article that I found somewhere over SlideShare talking about the subject (Scott Schwertly):
Last week, we discussed the difference between fear and anxiety. Our conclusion was that most presenters actually possess more anxiety than fear when it comes to presentations and public speaking. Given that reality, I want to unpack ways in which you can combat anxiety in your next speech.
Here are 3 essential tips:
1. Get the Blood Flowing
If you are a fan of exercise, then go for a run or walk the day of your talk. Studies have proven that the benefits of exercise have a positive effect on the nerves, lasting up to 12 hours. If you know you enjoy the endorphins that come with exercise, make sure you perform your activity within 12 hours of your presentation.
2. Rehearse, Don’t Memorize
Practice will build your confidence and reduce your anxiety. However, please note that there’s a significant difference between being well-rehearsed and coming across as memorized. Rehearsed implies that you are prepared, confident and can speak on the fly if needed. Memorized implies that you are dependent, lack confidence and are controlled by your talk, rather than you controlling it. Remember and run through key phrases and points, but don’t memorize word by word — the pressure of remembering all that will just add more to your anxiety!
3. Show Appreciation
Ultimately, you want to get into a mindset of appreciation. If your audience knows you want to add value to their life, you will immediately feel a sense of ease because it will define your purpose and role in the presentation environment. Simply, if you can demonstrate that you care about your audience, then they will be more likely to care about you. Perceived distance between the speaker and audience creates uncomfortableness.
Anxiety is a very subjective matter. At the end of the day, you know yourself better than anyone else, so choose those activities that will calm you best.