Giving a speech is intimidating. Winning over a crowd, even moreso. If you want to inspire the people you're speaking to when you're presenting, bring them to an inescapable conclusion.
Photo by The Open University
As The Art of Manliness explains, Winston Churchill was legendary for his speeches. While they played with words and rhythms, they were also built on rock solid arguments that drew the listener in. Every good speech should have a climax, and it should be as inescapable as it is inspiring:
Sometimes the compiling of evidence merely consists of saying the same thing multiple times, in slightly different ways. "If you have an important point to make," Churchill advised, "don't try to be subtle or clever. Use a pile driver. Hit the point once. Then come back and hit it again. Then hit it a third time -- a tremendous whack.
If your speech or presentation doesn't end with the obvious accumulation of everything you've presented so far, try to restructure a bit. Don't just let your argument taper off at the end without really going anywhere. The end will be what most people remember. Make it something worth remembering.
The Winston Churchill Guide to Public Speaking [The Art of Manliness]