I usually try to bring things that make me feel like I'm at home (like slippers or comfortable sweat pants, family picture, etc); a good magazine (Road & Track); a few cigars (probably didn't need to mention that). I also recommend packing a good travel alarm clock and a small flashlight (comes in handy when you get up at night in a dark unfamiliar room). Other than that, don't tap your feet in the bathroom stalls and keep your wallet in a front pocket.
Hope that helps.