The key to effectively using examples in your speeches is this: what is an example to you may not be an example to your audience, if they have a different experience. If you were describing a type of architecture, you would obviously show visual aids of it and give verbal descriptions of it, but you could say, “You pass an example of this type of architecture every time you go downtown-City Hall.” An example must be quickly understandable, something the audience can pull out of their memory or experience quickly. They are designed to give audiences a reference point.
Examples are almost always short but concrete specific instances to illuminate a concept. This type of supporting material is the first and easiest to use but also easy to forget.