Sane Airplane Travel - Breathing Space Blog
Wear loose and comfortable clothing while on board. Sitting in an airplane seat is confining--you don't need to add to it by wearing heavy clothing, restrictive belts, or tight shoes--unless you're meeting a client immediately.
If you do want to sleep--regardless of where you're sitting--as Gerry Tausch would say, don a baseball cap with a sign on the rim saying, "Sleeping, do not disturb," or simply, "Do not disturb." When you want to work, wear a cap with the words "On deadline, please do not disturb." Both messages work well.