BYO Food
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Greenberg recommends bringing your own snacks, including nuts, fruit, vegetables, crackers, and cheeses, but nothing that's cooked or involves a messy dressing or sauce. Some airlines have started selling snacks along these lines, so if you do forget to bring your own, purchase something that's difficult to mess up. "Nothing smells worse at 35,000 feet than a half-eaten bag of McDonald's," he says.