• Speak loudly but do not yell.
• Speak slowly and clearly.
• Smile, maintain good posture, and make eye contact with audience.
• Be succinct: keep your presentation simple but make your words count.
• Be engaging. How can your audience be interested in your presentation if you aren’t?
• Vary your tone, don’t “read” your script; even if you are actually reading it, it doesn’t have to sound that way.
• If you mention a foreign word, put it on a slide – some people will not really understand a new word without seeing it too.
• Likewise, if you come across a word you are unfamiliar with, look up the pronunciation or ask a professor/teacher/sage before you make a fool of yourself. Another solution would be to replace the difficult word with a synonym. (Example: change “prevalent” to “common,” etc.)
• Do not turn your back on your audience; it is extremely rude. ESPECIALLY do not go to the computer where your slides are loaded, stay there, and read from the computer without ever looking at your audience.
• Dress professionally when giving your presentation – like you would for a job interview. (Examples of what not to wear include shorts, flip-flops, a black bra under a white shirt, etc.)
•  Don't step back and forth, pace, or dance a jig out of nervousness when you're presenting. At best it makes you look silly, at worst it makes your audience seasick.

From: http://www.instructables.com/id/How-to-Give-a-Short-Class-Presentation-Competently/


Please with threes. Otherwise called the "rule of threes", this means that you create a presentation using a speech structure that consists of three main components: an opening, a body, and a closing. Manage these three major parts of a presentation and your speech will be organized every time. 

Get off on the right foot. Develop an attention-grabbing opening.

From: http://www.wikihow.com/Give-a-Powerful-Presentation-when-You-Have-Little-Time-to-Prepare