Since I've found myself in front of a few audiences, lately, I thought I would brush up on my public speaking skills. I was surprised (not really, I've heard it before) about how much body language can tell you about a person. In particular, I watched and listed to Amy Cuddy talk about Power Poses. Essentially, if you spread yourself out, you assume a power position, which means a confident and self assurance charisma that will be attractive.
Think of a turkey or peacock spreading out their tails. That's what humans should do--male and female. If you can't, before you find yourself in a situation, assume a spread out position. For example, go into the bathroom and raise your arms like you made a touchdown.
In the situation, itself, try to spread out. If you are standing, teaching, or presenting, stand with your feet spread apart. If sitting, place your arms on the armrests.
Do not, fold your arms or cross your legs. Not because its rude, but rather because it looks like a submissive, powerless pose.
Unfortunately, not only do I fold my arms, but I push my arms up into my sleeves. Not only do I cross my legs, but I cross them triply. That's three times! Why? Because I'm cold. It's that simple. Holding onto my elbows, I put my hands between by body and arms. It's a nice, cozy position. Likewise with my legs. I do it because it keeps me comfortably warm, especially in air condition.
But now, I'll try not to fold myself up. Not all the time, only when I need to give a Talk, otherwise, I'll stay nice and cozy and warm, folded up within myself.