No matter how informal a presentation, chances are you will want some way to keep yourself on topic. Our tendency in speaking is to continue on one idea, or to jump from point to point without fully explaining the connections. Like a thesis sentence, having a basic idea of what you are going to discuss and how you will do so will help guide an oral presentation. For professional speeches, simply reading directly from a paper may seem tempting, but a more natural tone of speech almost always comes across better. For more impromptu communication, a mental outline is sometimes all you will have time to prepare. Regardless of how much time you have to get your speech ready, organization is key.
People learn in different ways, including those who respond more readily to printed material than to verbal commands. Using visual aids is a good way to make sure that your ideas are explained fully to all members of the audience. Visual aids come in many forms, from pictures to charts to PowerPoint projects.
No matter how nervous you feel during a presentation, try to disguise your fear. Instead of looking down at your feet or at the paper in front of you, looking at members of the audience forces them to pay more attention. It also makes them more interested in what you are saying, because you appear to be saying it directly to each person individually. This is not just a psychological reaction, but also aural: if you are looking directly at someone, it is usually easier to hear what he is saying. The same works for verbal communication of any kind. The more attention you pay to the audience, the more attention the audience will pay to you.
Speaking clearly also means paying attention to how you pronounce words and phrases. In English, we very often mumble or slur words together, such as when "going to" becomes "gonna". Oral presentations require saying each word as clearly as possible. Doing so usually means speaking more slowly and deliberately than usual. Instead of speaking through your teeth and lips, open and close your mouth around each syllable. This will help make your words clearer and more audible. Time your breathing around your words so you can project sound directly from the diaphragm. If you are speaking correctly, people in the back row should be able to hear you clearly without you having to shout.