Don't pretend to give a real talk
PowerPoint allows speakers to pretend that they are giving a real talk, and audiences to pretend that they are listening. (Edward Tufte, 2006) Ouch! I am not against PowerPoint or any of the other slide applications. My view is that the slides should be made after the thinking has been done. I suspect many people start with the slides and all that choosing of themes and rearranging bullet points is actually a substitute for thinking.