I cannot stress this enough:
If there is a mic.
USE. THE. MIC.
A lot of people go "no, I'm a loud talker, I can just talk loud!", and the answer is no. Here's why -
2. Rooms with lots of ppl in them soak up sound - the audience muffles everything with their stupid clothes and bodies
3. If the show is being recorded, depending on how they're running it, your voice may not be picked up unless you're mic'd
5. Not using a mic when it's available is like using semaphore when there's a phone right there
-put it way closer to your mouth than seems appropriate. It should be like half an inch from your lips. Yes, it's weird. Yes, other people have spit on it. Yes, you're going to spit on it.
1. Our brains can EITHER listen to words or read words. Not both at the same time. If they're reading your slide, they're not listening to you. Why are you even there? This is a talk that could be an email.