Consider the lighting conditions
Digital presentations are infamous for their terrible typography. But I blame those who create the default templates for these programs. The qualities that make these layouts cheerful and attractive on your laptop often make them intolerable to an audience.
Why is that? When you’re writing your presentation, you’re probably sitting in a well-lit space, looking at your slides on a relatively small screen. In that context, slides with bright backgrounds and large type are fine. Your audience, however, will likely be in a dim room, viewing the slides at a much larger size. To them, the bright backgrounds and large type will be as pleasant as staring into a flashlight.
This insight yields a simple tip that will improve any presentation: choose typography for your presentation based on the size and lighting conditions where it will be displayed.