Your Style of Speaking
When you're preparing to give a presentation, one of the first things you need to consider is, what style should you use for your presentation?
In general, presentations ― whether they're TED Talks, Toastmasters speeches, sales pitches, or presentations to local groups ― range in style from conversational to theatrical (also called oratorical). One style is not better than another. They're simply different, and one is usually more appropriate than another in a particular situation.
"Conversational", as the term implies, is very much like the way one person talks to another person, except that a conversational presentation is usually one-sided and you talk for an extended period. "Theatrical" is more dramatic; it doesn't sound like a conversation as much as it resembles a Shakespearean performance.
As extreme examples, the question "What do you want to do after you graduate?" is conversational; it could be uttered in either a speech before thousands of people, or in a conversation between two people on a front porch.
In contrast, "I ask you one simple question — have you found your purpose in life? Your destiny awaits!" is decidedly theatrical. You wouldn't say that in a conversation; it sounds awkward and stilted. But spoken from the stage, it could be very effective (in the right circumstances).
Again, neither style is better than the other; it depends on the situation, and on the effect that you want to produce.
In his Inaugural Address, John F. Kennedy uttered the famous line "Ask not what your country can do for you. Ask what you can do for your country." ― stirring words that are remembered decades later. It wouldn't have been nearly as effective if Kennedy had said "C'mon guys, stop looking for handouts from the government. Do something for others!"
So for State of the Union addresses and other formal speeches, the theatrical approach is usually much better.
But imagine if Kennedy had been addressing a group of high school students getting ready to graduate. Saying to them "Ask not what your country can do for you!" would have left them cold. In that particular situation, saying "C'mon guys, stop looking for handouts from the government" would have been much more effective.
Those are extreme examples. Your particular presentation will probably fall somewhere in between. Not only that, but it can be quite effective if any one presentation is more theatrical in some places and more conversational in others. (Going more theatrical in a conversational presentation is a great way to provide emphasis. Going more conversational in an otherwise theatrical speech builds a rapport with your audience.)
In general, the theatrical approach is more authoritative and commanding; you're telling people what to do or think. On the other hand, the conversational approach is more peer-to-peer; you're providing helpful information or describing something.
So if you're speaking to your neighbors at a community get-together, or your fellow employees at a business meeting, or a small group of people at a luncheon, using a conversational style is usually your best choice.
But if you're speaking at a political campaign rally or some formal occasion, then a theatrical style will possibly work well.
For your particular presentation, pick the style that works best for you.