Fellow speaker,
If you are telling a story where you want something to be funny, exaggerate the gestures. Just as with humor you exaggerate the story you are telling, you can exaggerate the gestures in your story to point out that you are being humorous. For example, if you say, "I met this big guy and he was about...10 feet tall" stick one of your arms up in the air as high as you can to indicate the enormous height of this guy.
Exaggeratedly,
Tim
