Even the best speakers agree there is always room for their own improvement. The rest of us know we can certainly do better.
It's wise to work on your presentation skills even if you don't formally address large groups. Many of us can benefit from becoming more effective and polished in the boardroom, too.
An excellent collection of speaking tips, Speaking as a Performing Art, is offered on Guy Kawasaki's blog. They were compiled by his friend who is a professional singer, music director and...speech coach.
He recommends how to stand to project your voice, how to keep your mouth moist, how to use your hands and how to use silence. Great stuff.
Enjoy the comments, too; one of which is:
One other recommendation I heard which helped me and can give you a boost of confidence before a presentation: remember that the audience is on your side and they want you to succeed. They want to experience a great presentation! Thinking of an audience that way, instead of thinking of them as a group of critics waiting to pounce on your first mistake, frees you up to embrace some of these tips above.