Name everything you’ve done wrong this week and then everything you’ve done right.

If it was easier conjuring up the wrong, time to change things.

I have my students applaud each other heartily after they present their viewpoints

Positive reinforcement is the key to sustained confidence – congratulate yourself and others because building people up, not tearing them down, increases confidence.

Trying is more important than succeeding

A .250 percentage makes a baseball player lots of money – you don’t need to succeed 100% of the time.

Assume a virtue if you have it not (Shakespeare) 

If you assume your presentation will be effective, it likely will.  If you worry about whether it will, it likely won’t.

Another word for confidence is belief.