Every person I've ever met who travels loads takes time to bore me with their particular tricks of the trade. A few things always come up. Fresh fruit in tupperware. Evian spray. And YOUR MOST COMFORTABLE CLOTHES. It's a good point; only an amateur would wear ball-hugging skinny jeans rather than slouchy (horrible word) trackie bums.
But some are so obsessed with their image that they disobey rule number 1. That's why they fall flat on their face in airports.