Choose a topic about which you are passionate. Your enthusiasm for the topic will show when you present the speech, making it more interesting and enjoyable to watch. In order to be convinced by your words, the audience needs to believe you care about what you're saying.
Make the topic relevant to the audience. Explain how the topic impacts them and why they should care about it. Even if your topic is obscure, find a way to link the audience to the information. This will give your speech purpose and keep the audience interested.
Add your personal stories and explain you motivation for writing the speech, as long as it seems appropriate to the topic. Infusing your personality into the speech will help the audience connect with you as an individual and thus the speech will be more powerful.
Research the topic thoroughly in order to provide unique, detailed information. The best speeches balance broad concepts with concrete facts, examples and anecdotes. Speeches that are comprised of "fluff" alone lose relevance and are not convincing enough to be powerful. Give the audience facts to grasp and that they will want to share with their friends once the speech is over.
Repeat your main thesis, or any key phrases throughout the speech. According to the University of North Carolina at Chapel Hill, it's useful to repeat "buzzwords" throughout the speech so the audience can connect to the information.
Organize the speech so it flows logically and progresses toward a climax. According to MIT, the speech should have some sort of logical structure, such as a chronological or sub-topical layout. Build the speech to a point of action, where you emphasize the importance of the topic and explain what, if anything, needs to be done from that point forward. The most compelling part of your speech should be the end.