When you're meeting someone for the first time, or it may not be for the first time , make them eager to meet you next.... This also goes hand when you are making a presentation to a large crowd or in your class...
Here's the trick
If you make yourself be really happy
and pretend to be excited to see other people , the next time they see you, they’ll probably be a lot happier and more excited about it.
Some speakers use this and you wonder why people are excited when you see some strange political candidate. It's all in their minds!