To help people remember a notable point, say:

No matter how great of a public speaker you are, there’s no way anyone will remember everything you said. But highlighting what you want your audience to remember works remarkably at getting that idea to stick. “They can’t remember everything. You’re putting a little bookmark on it,” says Carmine Gallo, MS, communication advisor and author of The Storyteller’s Secret: From TED Speakers to Business Legends, Why Some Ideas Catch On and Others Don’t. “What’s uncanny is that this works so well, you can almost plant an idea in people’s heads.”
To give proof for your big idea, say:

Now that you’ve established your big idea, support it with three examples. Some studies have shown working memory can only remember three to five items at a time, and the upper end of that might still be too much. “Three is the most powerful number in communication,” Gallo says. “It could be because three is a logical progression – one doesn’t sound like enough, and five is too many.” Just keep the tone conversational – you’re not writing an essay, so phrases like “my three main points are…” can sound clunky, says Matt McGarrity, PhD, a lecturer of communication.
To make your points stick, say:

Repetition can do wonders in making people remember what you’ve said, especially if you use that rule of threes again. Whether you like the repeated phrase to become at the beginning or the end, just pick a pattern you like, and fill in the blanks with your message. “I typically refer to these as equations for eloquence and humans with the variable,” Dr McGarrity says. An A-B-B-A style (think: “Ask not what your country can do for you, ask what you can do for your country) is particularly effective, he says.