An introduction should be strong and strident, stepping into the void that has been left between the end of the applause as you work your way to the podium and that moment when you open your mouth and utter your first word.
An introduction needs to be clear, concise and provide insight and understanding for the audience, who at this point probably don’t know you from Adam. It needs to explain simply and easily the subject matter at hand before sliding neatly into the meat and middle your of your presentation, where you will expand on the tone and theme you have already successfully introduced.
Finally, an introduction should be the perfect counterpoint to the finale, the conclusion, where you draw all the the threads you have woven neatly together, tie them off and then snip the ends, leaving a perfectly complete and finished article.
And, as a demonstration of the above: