I found this interesting that making yourself on a day that you have a speaking engagement that you make that day as routine as possible prior to your speech. This will help in relaxing yourself.
A communication student provides tips in how to combat speech anxiety by breathing, having a conversational tone during the speech and to how keep (or at least simulate) eye contact.
Robert E. Burns a visiting lecturer at Bridgewater State College talks about Speech Anxiety and the use of his method called "The 7 P's of Speech Anxiety Reduction". Moreover, he talks about how himself overcame the fear to public speaking.
Deborah Grayson Riegel provides some insights about public speaking anxiety and how to overcome it with some simple and powerful steps like: breathing, renaming our emotions from scared to excited, among others.
The University of Houston offers a visualization technique to help cope with Public Speaking Anxiety. You can download either the mp3 and/or the transcript for free.
As I am a ESL speaker and i found it a good resource for understanding the anxiety of speaking and overcoming it for ESL speakers. I learned about speak slowly and clearly, and also about word choice for the speech that i am comfortable in speaking.
While this doesn't deal directly with speech confidence, it does deal with an anxiety-producing communication situation. This is posted for those group projects that many speech classes have to do, written by a fellow speech professor.
I liked the five points mentioned here to overcome the fear of public speaking, especially the idea of "You Don't Have to be Perfect." I have experienced during my speech preparation that aiming for the perfect speech leads to procrastination in work and further increase in the anxiety level. So, presenting the content of the speech with passion is the good strategy for making positive impression on your audience.
This article explains that the fear of public speaking of most people is going to give you the edge in front them if you learn to cope with the anxiety.
This website talks about how to choose a good speech topic. During my speech preparation, i felt that if i am comfortable about my topic or i know my topic well, it takes care of half of my nervousness about the speech delivery. So, i think having an interesting speech topic makes speeches enjoyable for the speaker as well as for the audience.