Jennifer Widom, May 2005
Here's some advice I sent to the SIGMOD '05 conference speakers (I was PC Chair). Some of the points were inspired by a SIGMOD 1995 note-to-speakers from that year's PC Chair Mike Carey, who in turn attributes Marianne Winslett and Catriel Beeri.
Plan very carefully what you can cover in the allotted time. You have 25 minutes, and a conscientious session chair will ruthlessly cut you off if you attempt to exceed that limit.
Design your slides with a large room and audience in mind. Use large fonts so your slides are visible from far away. As a general principle, don't put too much on each slide.
Given the time limit there's simply no way you can present all the results in your paper, so don't even try. Think of your talk as an advertisement -- your goal is to entice the audience into wanting to read your paper. Motivate the problem; describe your overall approach and your major results. If your work includes experiments, pick a representative graph or two.
Don't put everything you want to say on your slides and then read them during your talk. You will captivate your audience by forcing them to listen to you, looking at the slides only for cues and diagrams.
Keep your examples simple, emphasizing the main points, and give the audience enough time to digest each example.
It is strongly recommended that you practice your talk several times, especially if you haven't given many conference talks in the past. Time your runs; get your friends to listen and criticize.
If you are not a native English speaker, make an effort to speak slowly and clearly enough for a large audience to understand you. Even if you are a native speaker, you will need to speak loudly and clearly.
Position yourself carefully with respect to the screen -- be sure not to block the audience's view.
During the question & answer session at the end of your talk, be sure that your audience knows what question you are answering --