Some of you are experienced at giving presentations, while others may still be a little unsure. A common problem area can be your voice, so we encourage you to look at these videos.
The first explains how to project your voice.
To project your voice you need to speak from the diaphragm. This second clip shows exercises to help you do this.
If you have doubts about your presentation skills, then the issues covered in these clips are simply essential for you to understand.