Having previously considered the underlying purpose of your speech, it makes sense to consider the introduction as related to the type of speech you are giving.
Basically, there are two kinds of introduction: the direct and the subtle approach.
The direct opening immediately prepares the audience to pay attention to your speech. Its purpose is to create listeners who are attentive, receptive, and well-disposed towards you and the topic.
If the topic of our speech contains some controversial sections, we can build up goodwill by using a direct opening. Here the aim is to establish a rapport with the audience and, therefore, make the controversial aspects of the speech more acceptable to our listeners. If the nature of the speech is trivial, or the topic unimportant, we can use a direct opening to make our audience pay attention. But if the purpose of our speech is to support the insupportable, or attack a popularly accepted principle, we must use the subtle approach, unless we think we can capture goodwill by opening with an attack on our opponents. (I shall discuss the subtle approach later.)
Finally, if the purpose of our speech is non-controversial, in other words if what we are saying would reflect the opinions of our audience, we could choose to use either the direct or the subtle opening. If we choose to use a direct opening, we could start by demonstrating to our audience why the topic is an agreeable one which we all support, or we could start by simply outlining the contents of our speech. But if we do not wish to use the direct opening, we might begin our speech with a quotation, such as a law, a written document, or with an argument supporting our cause.
Since we wish to have our audience receptive, well-disposed, and attentive, I shall now show you how each state can be brought about.