Drawing upon both my Zen practice and what I've learned about the subject, I said, "Well, I'd try to remember, as the anxiety is setting in, that nervousness is perfectly normal. And that it will probably pass very quickly." Then as a Zen plug, I added: "The best thing, though, would be to learn how to accept the anxiety--don't fight or resist it, simply let it arise and fall away."
I could tell by the look on her face that that was not the answer she wanted. The last thing someone suffering from anxiety wants to hear is just to accept it. Trust me, I know from personal experience. But it's the truth; running from our fears is more exhaustive than it is effective.
We spend--or "I spend," I should say--most of our time and energy trying to run from the present moment. We try to shape and bend it to our will, hammer and polish it until it suits our liking. But the fact of the matter, what the Buddha taught us, is that life will never meet our standards.
Our lives will always know pain, anxiety, and fear; it's the human condition. But so is joy and happiness. If we could only learn to accept the present moment, regardless of its content, then and only then could we consider ourselves free. Until then, we are slaves to our fears, doubts, and cravings.
My teacher told me once that we aren't free until we understand that we aren't free; then we have a choice. It took me a while to understand, but I think I get it now, on more than just on a cerebral level.
To relate it to our public speaking example: we aren't free until we realize that we are running from our anxiety. Then we may experience a small glimmer of space, of freedom, in which we can choose. It's not the kind of choice we want. We want to say that we will never experience anxiety again, but that's simply not the case.
Instead we get the freedom to choose what we want to do with that anxiety (or any other "unpleasant" emotion/sensation).
The power, however, comes in the most unlikely form: acceptance of the moment, in its entirety. So the next time we stand in front of that crowd, our palms sweating and shaking, our hearts racing, we can resist the urge to run away mentally or distract ourselves, and instead just let the moment be.
Sorry if that's not the answer we want to hear, but it's the best I can give, because as far as I can tell it's the truth.