Question

How important are the principle of speech delivery in real life situation?​

Answer 1

Hey! I'm not sure if the principles of speech are universally recognized, but these 7 are mentioned in a popular article by amanet.org:

• Perception
• Perfection
• Visualization
• Discipline
• Description
• Inspiration
• Anticipation

If this isn't what you're talking about, I apologize; hopefully my answer can still help you:

• Perception - Think of this as your ego (its abundance or its lack); a big trait in public speaking/speech delivery in general is focusing solely on the topic of the speech. When you start worrying about the effectiveness of your delivery, that worry is recognizable and makes you less authentic.
• Perfection - "Perfection" is kinda the same thing, with emphasis on not over-thinking the small mistakes you might make.
• Visualization - If your audience can't visualize the ideas you're presenting, they'll quickly lose interest/get lost.  
• Discipline - Practicing/experience (obviously) makes you a better, calmer presenter.
• Description - Methods like "painting pictures" in your audience's heads/using rhetorical appeals to build a solid foundation for your claims is super important.  
• Inspiration - Speak to inspire, not to aimlessly stuff your audience with weak, boring, cliche ideas.
• Anticipation - Try to withhold key ideas for a little bit/linger on other information to create the feeling of suspense; when you create long-lasting interest, you become a more memorable speaker.

Hopefully I was of some help!