While we're on the subject of what to wear while flying...
PLEASE bring a fresh set of thick socks if you are going to take off your shoes!!! Put them on over your current socks during the plane ride (pretend they're your "plane slippers"). Take them off to put your shoes back on at the end of your flight.
Voila! Now the plane doesn't smell like your FEET!! The thick "plane socks" keep the stink sealed inside. And they keep your feet warm at 30,000 feet. (pun)