Be brief Deliver your points as concisely as you can. If the audience loses your drift it will be difficult to bring people's attention back to you. And use specific language that paints a picture. General, abstract words are dull.
Prepare, prepare, prepare A well-prepared speaker who knows his/her topic back to front always delivers great speeches. Remember that audience members might ask you specific questions about your topic after the speech.
Know your speaking environment The greatest speaker in the world with a poor sound system may lose much of their impact. Make sure your sound, props and lighting suit you and support your topic.
Look up It's important to maintain eye contact with your audience. It lends more force to your words and will mean your voice is projecting outwards rather than into the floor. If you are using props, avoid the temptation of looking at them rather than the people you are addressing.