Presenting involves elements of luck, I think we can rely less on luck...

After a series of extremely well received talks for the Atlanta .Net group I almost bombed last time. Not a total disaster and luckily few were present to witness it. I had given the presentation very successfully twice before, so what happened?

The Excuses

Late notice: I stepped in very late to fill the slot and did little preparation
Lack of Preparation: The only preparation was testing the demos and skim reading slides
Lack of enthusiasm: Lariam still affects me slightly, that was one of those weeks

Bad Luck

No crowd interaction: Advertising talks well in advance gets the word out and brings in people really interested in the subject - just one eager audience member can spur interest for others
Bored Blank faces: Need to learn how to handle this

Problems with my Old Style

Need short 10/15 minutes segments: The Cruise Control .Net talk was pretty technical, each section building on the last. If I lost an audience member they stayed lost. If one demo fails it could destroy every subsequent demo.
Relying on audience interaction: Good interaction makes for killer presentations - everyone learns and everyone has fun. I was relying on it, don't!
Deja Vu: When giving the same presentation several times it feels insincere, especially when repeating jokes. This must be an experience thing, Comedy School could help too.