Forget the Sweats
Stylist Cher Coulter recommends layering breathable basics—cotton T-shirts, light wool sweaters—over tight, stretchy jeans, which maintain their shape after hours of sitting. Finish with a drapey scarf, which can double as a blanket, and slip-on ankle boots. "Wear a shoe that needs a sock," she says. "There's nothing worse than going barefoot through security."