Truthfully, I try not to do any of those things. I like to be the "off-chance" or "spur-of-the-moment" magician. So, basically, I do the routine kind of nonchalantly (and for those of you who think this is bad showmanship, trust me, it actually does work) (plus, it's more of my real personality). When I get up to the mind reading part, maybe I pretend to concentrate a bit, but more concentration like looking up at the ceiling, as if I'm making some kind of calculation.
Of course, I DO occassionally do what I call the David Blaine pose, where I just look like I'm concentrating like mad. I would NEVER be caught dead doing what I call the Criss Angel huffing in pain thing (although I don't think he's a bad magician).