One of the ways, to cut the stage fright short is the 'Standing Swing' where we instinctively move in hips in, hips out position, like kids reading out in class. Its a way to trick the body into thinking we are in the fecal position.
Secondly, stage fright can be overcome with that rare pause, where after finishing a paragraph, you take in a deep breath, amateurs rarely do it, and intend to carry on, as if they would miss the train.
Thirdly, the tempo matters a lot, often, people try to go faster then their normal speaking speed, to which they are not accustomed to, leading into a unneeded stress on the brain to connect, produce and understand faster, leading to a mental stamina drain.
A good way around the first time stage fright, written in books is the "talk to your friend in the crowd" technique.
Always, you would find that kind soul in the crowd, looking dead into your eyes, and giving you a validation nod, each time you speak, very often, this is someone you have a good relationship with, a friend, family or admirer. Just look into his eyes, and start talking, forget the rest of the crowd, as he agrees to everything you say, you would find it easier to deliver your speech.
A side technique, that requires preparation is to keep the contents of your speech simple, and short. Don't use words you are not familiar with, use the words, you most often use, even if you have to be a bit repetitive, your first speech needs to do a good job, don't aspire to be JFK on your first shot.
Thats interesting. Public speaking advice from politicians would be awesome. They have to deliver moving speeches and be able to respond intelligently on the spot to questions they haven't heard before. I'm sure they would have a lot of great advice on how to deal with stage fright and think clearly in those situations.
Besides, polititians have teams who prepare everything regarding their image, speech, questions and responses, so they can focus on performing.
I didn't do anything fancy to get over my stage fright. I simply took every opportunity to speak publicly that came my way. I knew I was going to suck, but I also decided that the only way to stop sucking was to force myself to get better at it.
Each time, I tried to focus on one specific area of concern, e.g. talking too fast. I would practice giving the talk very slowly and record myself talking. That turned out to be very helpful, because I realized that I was actually talking a lot faster than I thought I was talking. Repeatedly doing this helped me to recalibrate my perception of how fast I was talking.
Over the past several years, I've noticed a few things:
* My pre-speech anxiety has declined from full-on trembling hands, quavery voice, nausea and so on to a mild nervous excitement that I can manage with slow, deep breathing. Once you've actually experienced giving a terrible talk, you get a more realistic (i.e. less catastrophic) sense of how bad it is.
* My talks themselves definitely suck less than they used to. I'm still not what you could call a good public speaker, but at least I look and sound reasonably comfortable on stage. I've gotten slower, though not slow enough, and I am generally able to stay on message.
* I tend to use my slides as cues for what I want to say at each point. This occasionally backfires when the stage is set up so that I can't easily see them.
My goal is to be a good public speaker. Maybe in five or ten years I'll get there. In the meantime, it's a work in progress.
Regardless, do improv.
Let me recommend the book Impro (http://www.amazon.com/Impro-Improvisation-Theatre-Keith-John...), in particular.
So during my graduate coursework (CS), there were a couple of courses which required the class to review and present various papers. When my turn would come, I would prepare really well, make good notes and I would say reasonably fine slides. But then, when I would present, I would just lose the context when going over the slides. Eventually I started keeping more text on the slides and would end up reading off it, which is awful for the listeners.
Is this stage fright? Or perhaps poor memory? Or something else may be?
I encountered this once and I suspect it was because I was thinking about presentation, not focused on delivering my point to the audience, not caring about it enough. Possibly also the audience that time didn't really care about my point. (Hard to find origin, as factors seem to worsen one another: you care less → audience cares less → … → your thoughts wander, you lose context.)
I prescribe to Malcolm Gladwell's method of preparation  in that I write out every single word of my talks beforehand and more-or-less memorize them. It's not my explicit goal to memorize every word, but I go over the words enough that that's essentially what happens. I actually end up memorizing key sentences and phrases more than words. Even moments that I seemingly "ad-lib" to the audience -- jokes, side comments, "random" anecdotes -- are written out beforehand. That way when I'm in the moment I can focus on delivery and not content.
I think the biggest driver to my anxiety of public speaking was the possibility of sounding stupid, but as long as I have the confidence that I've written out a good argument beforehand then that goes out the window. I stick to the script because I know the script will work.
As far as mentality goes, there is no better feeling than looking out into an audience of people and see them staring back at you, listening to every word. No smartphones out and no sleeping, just attention. While I still get a little nervous, it's nowhere near what it once was, and I actually look forward to connecting with those whom I've been invited to speak with. My excitement for that connection has started to trump my nerves.
Clearly I'm not in the camp of "don't prepare and just go wing it, it'll be more natural" because it really opens up the door for panic-induced disaster. And I really hate sitting in a talk that the speaker is clearly unprepared for. It's unprofessional and disrespectful. If people are going to give you the respect of their undivided attention, give them the respect of real preparation.