Lots of great advice here... I'll add my 2 cents- for what it's worth.
Keep your powerpoint pages very simple and basic. Choose a theme in Microsoft and stick to it- that way the presentation is consistent. But keep the graphics to a minimum. All the fancy graphics become distracting after a while. In fact, titles is about all you need:
Start it up when you come up to the lectern
Screen 1. "Experiences with Autistic Children
-Presented by Foppishbum
Thank the MC
. Set up the lecture: who you are, why you are there, why this is relevant to the audience...
Screen 2. A "Table of Contents" page The three or four basic points you are going to be discussing
Go over these points
Screen 3. Topic 1, Subtopic 1
Screen 4. Topic 1, Subtopic 2
Screen 5. Topic 2, Subtopic 1
Second-Last Screen: Review Page
Do a recap of the major topics you've covered
Last Screen: Thank you!
Building your powerpoint like this will help to organize your thoughts and keep you on track. If powerpoints get wordy, the presenters have a bad habit of simply reading the powerpoint- something that the audience can do by themselves.
* * *
Before the presentation takes place, make sure the equipment is set-up and working. Don't take anybody's word for it: 1/2-hour before the lecture is about to begin or something like that, fire it all up. Make sure the projector is working, the screen comes down, the computer is prepped and the presentation works as it should.
If you're using a microphone, do a sound check. The microphone should be about If it's a mic on a stand, adjust the microphone stand or have it adjusted for you so you're comfortable with the mic about 2 inches (4-5 centimetres from your mouth.. You should never have to reach up or down to speak into the microphone. If it's a clip-on microphone, make sure it's switched off before you begin your speech and... and switch it on as you approach the stage. During the sound check, have somebody at the back of the room give you the thumbs up when they can hear you well.
These exercises will ground you and give you confidence that you will soon be controlling the room.
As for preparing for the speech itself, keep it simple; Less is More. Keep technical jargon out of the speech, unless it's absolutely necessary. Build it numerically, just as I suggest you do with the powerpoint:
THANK THE MC
-Who you are
-Why you are there
-Why this is important to your audience
-Lay out what you're going to talk about. List major topics: leave the sub-topics to later
"While I'm talking about **(Topic 1)**, I will cover **(Sub-topic .1)**, **(.2)**, **(.3)**."
1.1; 1.2; 1.3
"Turning to **(Topic 2)**, I'd like to share with you **(.1)**, **(.2)**, **(.3)**.
2.1; 2.2; 2.3
"And finally, **(Topic 3)**. These three points I'll discuss now: **(.1)**, **(.2)**, **(.3)**.
3.1; 3.2; 3.3
-Review, without detail, each major topic point
-Remind your audience why this is important to them
THANK THE AUDIENCE
(Switch off the mic, if it's a lapel microphone)
* * *
BEFORE THE PRESENTATION:
REHEARSE, REHEARSE, REHEARSE. Rehearse until you're sick of talking about it. Envision the 300 people while you're practicing. Rehearse it until you are completely fluent with the order of topics, and the transitions you plan to use between them.
Write the speech if you must, but your presentation will be a million times better if you do it from memory (triggered by the powerpoint presentation -and/or- cue cards)
Take no drugs or alcohol to calm the nerves. Coffee will make you feel worse- and maybe even make you want to pee. It's the nerves that keep you sharp. It's stage fright. And it's a good thing. The nausea comes from poor breathing. Breathe from the diaphragm. (Breath deeply and slowly) As the presentation comes to the end and you know you've made it through in one piece, those jangly nerves will release and you'll be flooded with endorphins. (Best high I've ever had was finishing a speech in front of 1000 people)
DURING THE PRESENTATION:
During the speech, take your time. Relax. A 3 second pause will feel like an eternity but the audience is busy taking in what you have said. Take a deep breath: that takes about 3 seconds and is not an unreasonable thing to do on stage- heck, the audience expects that you do from time to time!
B-R-E-A-T-H-E & D-R-I-N-K W-A-T-E-R
Stop and take a drink of water now and again. Take a bottle of water with you. Between points is a good time to take a swig- your audience is absorbing what you've said and anticipating what you are going to say. Let them!
I find eye contact a good thing. Scan the room and simply meet people's eyes from time to time. Hold their gaze for a second and move on. Look at the front row. Look at the back row. Look across the middle.
O-W-N T-H-E S-T-A-G-E
You are in control of the room. If you can, and if you can stand it, watch some evangelical preachers on TV
with the volume turned down. Watch their actions, observe how they command their audience's attention. If you make a small mistake, don't panic. Take a breath, a mouthful of water *reset* and move on. If you make a big mistake, acknowledge it, fix it, and move on.
Don't say "This is my first time", in an effort for everybody to go easy on you. They will anyway. 9/10 people would rather not be in your shoes and so just standing up in front of them is enough for you to earn their respect.
Don't expect perfection. Politicians have to get it right. You don't.
Be yourself. The only person that has to be present on the stage, is you. You don't have to imitate anybody because you are who you know best.
Sorry- my Toastmasters lessons I share to others in one posting. But I hope this is helpful.
Good luck, my friend. You'll be fine.