13. Finish strong. Always be sure to have a satisfying conclusion to your presentation in which you make clear to the listeners what they now know. It creates a warm feeling in the minds of your listeners and shows them that they've really learned something from your talk—which they probably have.
14. Welcome interruptions. Some speakers are terrified that someone will interrupt them with a question or comment. Actually, this is one of the best things that can happen, because it shows that someone in the audience has engaged with what you're saying, and, if you have the time to offer a brief response, it can actually lead to genuine progress on the point you were making. And two-way conversation (assuming you're minimally good at it) is always a tension-reducer.
15. Know when to stop lecturing. Certain presentations–especially in advanced or upper-division classes or seminars–can require you to present some material, then lead a discussion. Be sure to attentively listen to any comments or questions your classmates might raise before starting on your answer. And in a discussion period, never lecture (only discuss), and be sure to answer exactly the question asked (don't offer up more canned–but irrelevant–material). In many classes, how you discuss is as important as how you present.