I came across 10 Tips For Successful Public Speaking on the Toastmasters International website and wanted to share it in case you have not come across it there.
1. Know the room.
2. Know the audience.
3. Know your material.
4. Relax.
5. Visualize yourself giving your speech.
6. Realize that people want you to succeed.
7. Don't apologize.
8. Concentrate on the message -- not the medium.
9. Turn nervousness into positive energy.
10. Gain experience. Experience builds confidence.
I think these tips lay the basic foundation of giving a great speech.