The key is to wear clothing that is loose, all the way down to the bra. You will be so, so thankful you didn’t overlook this article of clothing!
The only article of clothing that should be tight would be compression socks if you choose to wear them. Yes, they can be a bit uncomfortable at times, but they do help you stay safe from blood clots (DVT) that can occur when flying.
Actually, layers can do more than keep you warm: they help you to control your body temperature when the plane’s temperature can vary.
If it’s a short flight, you might be fine with a bit of chill on your legs; you can even bring a scarf to use as a little blanket of sorts. Having cold legs on long flights, however, will only add to your discomfort.
Because 10 hours into a 14 hour flight, every little annoyance will be doubly annoying you (if you aren’t one of the blessed people who can sleep on planes).
If you are bringing a pair of tall boots or something else that takes up a lot of room, wearing them onto the plane will save space in your luggage.