To maintain freshness on a long-haul flight, the "Golden Rule" is a multi-layered hygiene strategy. Start by wearing loose, breathable natural fabrics (like cotton or merino wool) which trap less odor than synthetics. Pack a small "hygiene kit" in your carry-on containing a toothbrush, travel-sized deodorant, and unscented body wipes to clean high-sweat areas mid-flight. Staying hydrated is also key, as dry cabin air causes "airplane breath"; drinking water and using mouthwash or xylitol gum helps keep bacteria at bay. Avoid heavy, garlic-rich, or spicy meals 24 hours before flying, as these scents can be released through your pores. Finally, keep your shoes on; if you must remove them, ensure you are wearing fresh, thick socks. A quick "sink-scrub" in the lavatory during the final two hours of the flight, followed by a change of t-shirt, can make you feel and smell like you just stepped out of a shower.