Here’s the Catch-22 of Fashion Week: You’re supposed to look ready for your street-style closeup 24/7, yet you’re averaging around 4 hours of sleep a night, going on countless showroom visits and subjecting your skin to a few international flights to boot. What’s a gal to do?

We turned to Bettina O’Neill, Barneys’ vice president of cosmetics & fragrances, for some tricks of the trade. Below, she tells us just what to pack in our Fashion Week luggage to keep us looking fresh, rested and Tommy Ton-ready—keeping in mind that our Manolos have already claimed most of the space…