Do research before selecting the topic you will present. Make sure you have enough supportive data to comprehensively present factual information about the topic.
Keep your audience in mind as you choose the topic. Select a topic that is neither too complex nor too simple for the intended audience.
Keep your objective in mind. This will prevent you from straying off topic and help you to organize key points and information.
Find updated and relevant information. You will appear misinformed and foolish if your topic is not current. Find several new or interesting facts to share with your audience. Be sure to research every fact to make sure it is correct. Use examples and supporting data to strengthen these facts.
Make sure your supporting evidence is credible. This is very important in an informative speech. Also, remember to cite resources properly.
Write the introduction of your speech last. This is a good idea because by the end of your speech writing, you will already know a lot about the topic and what you're going to say.