First, arrive in comfortable clothes. Wear a top that you can adjust -- sleeves that roll up are perfect -- or go all NFL Sunday on it and change into a sweatsuit or pajamas once you hit cruising altitude. If you go this route, a soft alarm 30 minutes before landing will give you a chance to change back into your grown-up get-up.
Get a blanket and buckle your seatbelt over it, to ward off any questions about you being buckled in. Then bust out your neck-hugging travel pillow. Pro tip from flight attendant turned travel writer Heather Poole: If you’re stuck in the middle seat, wear the travel pillow backwards so that you can rest your chin on the front of the pillow to avoid leaning on your neighbor for support.
A sleep mask or baseball cap is crucial, since even the dim light from someone reading 12 rows away may trigger the photosensitive receptors in your retinas. Ear plugs are cheap and easy; less cheap and less easy -- but probably cooler -- are noise-cancelling headphones. If you want the full merit badge, put essential oils on your stuff to ward off weird odors and give yourself some relaxing, homey smells.