Are you planning a long-haul flight?
There are definitely some things you shouldn't forget to take with you in order to have a comfortable flight.
Air companies usually offer you a travel set consisting of a pair of slippers and a blanket, but this is not enough to ensure you comfort.
When I use to fly long distances I never forget to take a travel pillow and a sleep mask with me, otherwise I can't sleep.
These expedients helped me to sleep even all the way long to Fiji islands.
Another useful thing you shouldn't forget is the travel set with bottles essential to take shampoo, liquid soap, deodorant, fragrances and any other liquid thing with you; The 100ml restriction will no longer be a problem!
Remember to be organized, when you travel you need to use and reuse your tickets, money, passport and pens and this travel document holder will really help you!
Finally how to choose your cabin bag?
Personally I bought the Cosmolite by Samsonite because I found it nice, comfortable and very lightweight, so you will have more weight to devote to your things.
Don't forget to pay attention to suitcase sizes because many air companies are very strict about that, check on their company websites to be sure you're bag is OK with their cabin baggage policies!