Question

How can a speaker most effectively persuade the audience in favor of a certain viewpoint?

Answer 1

 When writing a persuasive essay (or giving a persuasive speech) the speaker should tell them what you're going to tell them, tell them, then tell them what you told them. Also the speaker should present the opposite viewpoint and then disprove that point with their point.

Answer 2

It depends on the kind of audience, but it is a good idea to use modes of persuasion.

The speaker can appeal to the moral side of the audience by using ethics as a rhetorical appeal, which is called Ethos.

Another way is the appeal to emotion. Making the audience become emotionally invested in something is a good way to make them think about something the way you want them to. This rhetoric appeal is called Pathos.

Depending on the kind of audience, specially a more academic one, nothing but logic and sound reasoning is going to change the audience's mind. And if that is the case, you must have a lot of evidence and logical reasoning to use as a rhetoric appeal. This one, we call Logos.