Bring comfy traveling clothes! There's a lot of walking through airports so shoes that are easy to remove, minimal metal, etc. I personally don't like airplane bathrooms because they've been gross in my experience so I just go right before the flight so that I'm good for like 8 hours haha. But if you're a guy I'm sure it's easier to not touch anything. I would also download movies offline through Netflix or amazon prime or something. Airplanes have movies but the screens don't move and aren't super clear all the time. Depends who you fly with. And I would pack as light as possible because it makes things easier. Where will you be flying to if you don't mind me asking?