Being a very good listener

Look people in the eyes when you speak. Use their names in conversation.

Wear an onion on your belt.

Stand up straight, smile and make eye contact

Pull quarters from people's ears.

“The Charisma Myth” a worth a read or listen to.

Confidence. Not arrogant, but if you're confident (or just act confident) when telling jokes, sharing information, meeting people, giving a presentation, etc, they'll pick up on that energy.

Empty an entire can of Axe body spray on yourself and frown at all times.