I have noticed that it is easier to do full rehearsals of talks with slides than it is when using only notes. The slides make the rehearsal more fun, too. Storyboard your presentation . PowerPoint helps you think structurally about your presentation. You know you need an introduction, a conclusion and main points, all supported with arguments, stories and examples.
Some people work best with outlines.
PowerPoint will automatically turn an outline into a set of slides. I like to sketch out my presentations as a series of slides. I can then conceive my presentation as a set of slides and sketch what kind of graphic I want, how many bullet points and where anecdotes and examples will fit into the talk. This process makes it easier for me to imagine the presentation in its entirety and visualize my performance. Never forget your conclusion slide .