So how do you really make your audience like you?
Here's the reality, you can have perfect eye contact, good hand gestures, never say ah or um, go through your PowerPoint slides perfectly and your audience still doesn't like you. Why? Because they get the sense that you're focused on me, me, me, my content and my stuff!
“Aren't I great? Look at my expertise!” If you do that, your audience is never going to like you, you can be technically devoid of mistakes. On the other hand, if your audience feels like you're really trying to help them, you're giving them information, you want to help them, you want to make them better, they'll forgive all kinds of mistakes.
Your shirt tail can be hanging out, you can have “uhs” and “ums,” your grammar can occasionally be off, if you're really giving good useful information to your audience and they get the sense that you care about them, that you want to help them, and you're giving them good information, they'll forgive all the other problems and they will not only like you, they'll love you.