One of the main areas that I address in my role as a voice coach for business is pace. This is about varying the speed of speech within the context of what you are saying and the situation you are saying it in. Engagement at the start of a presentation is important, so you should put more energy into your speech and up the pace for a short while.
However, as Paul Carr explains here, a slower pace is important for clarity. As I always tell people on my courses: reduce the pace when you need to reveal information. This allows people to digest the detail and it also stops you from tripping over your words.
Watch this video of Paul Carr as he tells you about boosting clarity:
