Editor’s note: Sign up for Unlocking the World, CNN Travel’s weekly newsletter . Get news about destinations, plus the latest in aviation, food and drink, and where to stay. CNN  —  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