So, don’t screw it up.
There are two things that ruin a possibly good speech for me: The Apology and The Resume. The first happens when the speaker steps up to the mic and proceeds to explain how they don’t normally speak in public, how they are technically challenged with or without their PowerPoint, and how nervous they are to be in front of a group of people.
My brain sighs with the anticipation of listening to a speaker who really doesn’t want to be there and has no idea how to take control and make their presentation. From that auspicious start, the audience does not feel sympathy or empathy for the speaker, they feel cheated.
You are in control.
Taking the stage, stepping up to mic, or rising from a crowd to make your point you are immediately endowed with authority with few exceptions. (For instance, if you are that quirky person in the meeting who always has some bizarre point to make then the groans will be audible.)

Your audience wants to listen, they want to hear what you have to say, even if they don’t agree with you. Most of the time, speakers are asked to proclaim their wisdom to a crowd that is eager to listen so don’t discourage them by telling them you have no idea what you are doing. Be confident, have a plan, practice what you want to say, and then get up and say it.
We trust you.
The second thing that ruins a good speech is when the speaker extolls their life history when it has nothing to do with the topic. The audience trusts that you have the credentials to talk about your topic. There is no need to bring out your eighth grade report card or regale the captives with your college years, first marriage, career progression, and spiritual awakening unless it has something to do with the topic.
You can avoid this by allowing a speaker to write a 30 second introduction that the emcee can recite and end with, “Please welcome, INSERT NAME OF SPEAKER.” This gets the ball rolling right into the expected subject and the audience is thrilled to have more time to hear your expertise rather than your resume.
Punctuality Counts
There is one more bugaboo that makes me clench my teeth, and that’s the speaker who announces they are going to ignore the time frame they have been asked to fill. Usually interpreted as they will continue talking until you tackle them or turn off the lights. If you are the speaker, be considerate of your audience and claim your authority by confidently presenting the material requested in the established time frame. That is, if you’d like to be a welcome and frequently requested speaker.