Rehearsing how to exhibit emotion during a presentation is critical, a technique that works is the happy-sad exercise where it's necessary to pretend to be as happy as possible, and then quickly shift to being as sad as possible, provides effective training in this area. A friend assists in this exercise and must shout out when to change emotions after being satisfied in the way the feeling has been shown, for example, by successful use of gestures, facial expressions or tone of voice.
Rehearse at the actual place where the presentation will be delivered or a place that's similar. Deliver the final rehearsal in this space as well, making sure this run-through is as near to the real presentation as possible; that means testing and using any equipment that is needed. This real-world style of rehearsing imparts confidence and naturalness and adds freshness to the overall presentation.
Use rehearsal techniques that ensure the nonverbal messages being transmitted during the presentation don't offend, but attract. For example, take command of the body by practicing standing erect with the chest expanded; this stance projects authority. Rehearse making eye contact with the audience by taping a picture of a few people to several chairs, and then practicing speaking directly to them.