Aircraft lavatories are tiny contrivances, about the size of a small closet or a very large Manhattan apartment. So maneuvering in and out of your pants can be, well, tricky. (That's why someone invented Claspies.) Lest you drop your wallet in the toilet or fall and smash through the bathroom door, wear something that isn't likely to cause difficulties in the plane bathroom. Avoid bodysuits or complicated wrap shirts or dresses, as well as long pants or skirts that may graze the unsanitary (and often disturbingly wet) lavatory ground.