I fly a lot and have my carry-on down to a science these days. First, airlines are germ-ridden places, so I put in a travel size pack of antibacterial wipes to wipe down my armrest, seat-back-tray and the viewing screen in the back of the seat in front of me. I also have a travel size hand gel because as soon as I saw a study about the bacteria in the water onboard planes I stopped accepting any water that was not seal in a bottle and I don’t wash my hands in the restroom sink. I’ve run across some fliers who even carry a lightweight seat cover that engulfs the whole chair, but that’s a little too much for me. If you use the seat-back-pocket then bring a plastic grocery bag to insert into it so your items don't connect with the bed of germs laying in wait for your book, iPod or other items you wish to keep handy.
Now that the germs are handled I concern myself with my entertainment. Charge all your electronics the night before and do carry-on your plugs because some planes now offer outlets. I still pack a good old fashioned book to read or a magazine just incase technology fails me for some reason or other. The earphones for my iPhone/iPod fit most airlines and I prefer mine to theirs and it saves a few bucks.
For my creature comforts I carry some soft warm socks, a pashmina (guys get navy or black and no one will think it’s anything but a blanket) and sometimes two for my in-flight blanket and for a wrap once I hit my destination. I’ve recently found the best ever neck pillow, but will do a little blurb on it at another time. I also dress in layers for flying as the temperatures vary so much from starting point to final destination.
Eating: bring your credit card because in-flight purchases can no longer be made with cash. But if you’re mindful of the TSA regulations you can bring your own food from home as long as it’s not a thermos of soup or some other suspect liquid. I usually pack those single serving tuna & crackers or just the tuna pouch & baggie my own crackers and string cheese. I’ve also had success with the hummus/cracker packs, apples as long as you eat it before your destination if the destination is outside the USA borders (no fresh fruits or meats). A few times I’ve had nuts taken from me as well when going into Mexico, but it was only a couple of times out of the dozens a time a year I go there, so not sure if they just wanted those raw almonds or they thought they were hiding some pest that would set off a national disease control alert. If you make your food from home I bring it in containers I can toss to lighten my load and on my return flight I stop at a market or worse case I purchase at the airport once I’ve gone through security. Before security all liquids must be tossed, but I’ve never been asked to give up my bottled water I just bought at the airport newsstand and I see plenty of Starbucks coming onboard; one man even spilled his on my beige skirt because he couldn’t handle all his carry-on so that’s my next tip… be thoughtful of other travelers and don’t bring food with strong or possibly offensive smells and if your hands are already full don’t add a beverage with a lid that comes off if you’re not holding it upright every moment.
My 1-quart ziplock bag varies depending on if I’m flying carry-on only or I have a checked bag. With a checked bag it is limited to a 3.4 or less moisturizer, hand cream and Chapstick and I add shampoo, conditioner, face wash if I have no checked luggage. I also carry the small travel toothbrush/picks with the tiny drop of tooth gel in the center.
I have one large-ish carry-all or tote that I can fit my laptop, a small purse and all my other goodies into that way they are separate so I can find what I need quickly yet in one bag to make the airline happy that I comply with the one carry-on and one personal item.
The other thing I like to carry-on is a smile. Flying has always been stressful for people who don’t feel at ease with their feet off the ground and since 9/11 even those who loved to fly are finding the lines for security and all the hoops we jump through to make it in and out of the airports a stressor. So, a smile goes a long way in helping those around you feel a little better and if my smile can inspire another smile maybe it’ll be a delightful flight.