Navigating airports and airplanes can be stressful at the best of times. As millions of travelers take to the skies over the busy holiday period, that inbuilt stress can hit new heights.But it doesn’t have to, just ask the world’s flight attendants. If anyone’s got surviving holiday travel down, it’s these aviation experts who fly every day, sometimes multiple times a day.To learn from their wisdom, CNN Travel chatted with Florida-based flight attendant Hunter Smith-Lihas, who works as a flight attendant on a major U.S. airline, and veteran Australian flight attendant-turned-psychologist Liz Simmons, to hear their tips, tricks and aviation secrets.Whether you’re flying home for Thanksgiving or heading abroad on a New Year’s Eve getaway, here’s a cabin crew’s guide to surviving the ups and downs of holiday air travel.Give yourself a buffer dayEveryone wants to maximize their vacation time, but flying at the last possible minute is a risky …