Rule #9: Be concise

Unwritten Rule of Engineering #9: Strive for conciseness and clarity in oral or written reports.

The trick is convey the maximum of significant information in the minimum time, a valuable asset to anyone. … Start at the beginning, with the most important fact, the one the audience must know before learning more. Often this is the conclusion itself. Progressively broaden the pyramid by constructing each sentence upon its predecessor.

One of my favorite sources on how to present more effectively is Presentation Zen; another is any book by Edward Tufte.