Sketches. Sketches are simplified representations of what you are talking about. If you don’t draw well, check out children’s coloring books for line drawings of objects that you can trace. Make the sketch first on paper, then enlarge it or transfer it onto a transparency with a copier. Mark Peterson used a sketch on an overhead transparency to illustrate a speech on buying a bicycle. As he talked about making bar-to-pedal and seat-to-handlebar measurements, he said, “Let me show you how to take some basic measurements.” When he finished his demonstration, he turned off the projector so that
would not be a distraction during the rest of his speech.