Fundamentals of Public Speaking
Master these, master public speaking.
The fundamentals of public speaking are comprised of a few basic skills. When we improve in them, we simultaneously improve every speech we give from that time forward! Here are some of the fundamentals going from the more basic to the more advanced, along with things that we can do to improve in them.
Pronunciation. It's fairly basic, but if you don't pronounce words correctly, you lose a lot of credibility with your audience. Check with the dictionary if you're unsure about anything.
Articulation. Don't slur words. It makes you harder to understand and less professional looking. To practice articulate, put a few marbles in your mouth and speak for a while with those. When you take them out, you're words will be nice and clear. (While it's not as common a problem, over-articulation can also detract from your presentation - it makes you sound canned and stiff. If this is your issue, be certain to relax before giving your speech.)
Projection. Your speech doesn't matter if your audience can't hear what you're saying. Practice breathing to your belly, using your diaphragm to breath in deep. Support your words with a strong breath of air.
Inflection. Here's where we get into the real art of speaking. What do your words sound like? Said one way a word may mean one thing; said another, it might mean the exact opposite ('nice,' for example, can be a genuine compliment or a sarcastic derision). Record audio of yourself speaking, then play it back and listen to how you sound.
Rapport. Also called audience engagement or audience connection. Developing this connection can be one of the hardest parts about giving a speech. Practice in front of a mirror so that you can see yourself. Take a video of your speech. Analyze it and fix your mistakes, improve your weaknesses. Then, when you're performing, be aware of your audience. Speak to them (not at them). They'll listen.
Mastering these fundamentals of public speaking takes effort, and no one is ever perfect. But when we word at these areas, every speech we give will be a step above the last.