With a Classic Structure
In a speech where you're trying to persuade someone, the classic structure is called "Problem-Solution." In the first part of your speech you say, " Here's a problem, here's why things are so terrible. " Then, in the second part of your speech you say, " Here's what we can do to make things better. " Sometimes it helps to persuade people if you have statistics or other facts in your speech. And sometimes you can persuade people by quoting someone else that the audience likes and respects.
Keep an audience engaged in your speaking all the time, focus their attention by adding questions and personal appeals, and never remove keen fingers from the pulse of their reaction. If sections of your speech are of different length, then you may be sure, that this will significantly lower the rate of peoples' growing tiredness. Place the most important statements of your message right after the halfway point, because this is where their attention reaches its maximum. Let the people know that they are on the equator of your speech, then emphasize the essence of your message, and after that, decently climb down to the completion. There must not be any headlong flight to the end, simply and briefly summarize all your points and restate your main conclusion. The final part is the most protruding and memorable as well as the beginning, so give it some stir and make it prominent, so that you can leave the rostrum to the round of cheers and applause.