Vary the volume of your voice, its pitch, its tempo, so that it approximates conversational tone but remains formal. Speak at a pace that allows everyone to follow you without their attention wandering. You do not have to talk constantly when making a presentation. Give the audience the chance to catch up to you and mentally organize what you are saying. Pause at end of each sentence and especially at the end of each paragraph.
Pauses are voice punctuation as important as written punctuation.
Visual aids are encouraged to be done on a word processor and produced on overhead transparencies. Visual aids are to assist the audience in following the presentation. Lists are encouraged to be put on visual aids for audience assimilation. Visual aids can be used to direct attention away from you personally to the facts under discussion. They can also help the presenter stay on track.