"Try not looking directly at your audience" is awful speech advice.
Being a speaker myself, I'll tell you that audience-eye-contact is essential. Both types of it, too. There's the "scan the crowd" type of eye contact, when you just pretty much look around at the audience, but not to anyone specific, then there's the "locking" type...where you do look at people specifically.
If you're trying to make this a good speech...use both types.
Avoid using words like "um", "uh", and "like".
Make sure you've got good posture. Don't lean over to one side, or stand in any other sort of way that might make them think you don't care. Body language is another essential part of speaking.
Other then that, make sure you're loud enough, and smile. : D