1. Keep socks in your purse - I hate wearing sandals or flats when going through security because most require you to take your shoes off. I always keep a pair of socks in my purse to put on so I'm not barefoot walking through security as well as for when I'm on the plane. My plane rides are usually longer than two hours which means I like to nap. Having said all of that, I usually take my shoes off and wear my socks. In short? KEEP SOCKS ON YOU!
2. Bring snacks/food from home - You aren't allowed to bring liquids/drinks with you through security so you have to buy those once you're cleared and on your way to your gate, but you can bring food! I usually bring chips, sandwiches, bread, crackers or something of that sort. You are allowed to bring this with you through security! You're welcome!
3. Use the bathroom before you board the plane - Not only is there only maybe three bathrooms on the plane, but the bathrooms are also super cramped! You'll usually be able to find one near your gate so go use it before boarding your flight, your bladder will thank you.
4. Bring a small blanket - Ever notice how cold the plane tends to be no matter what time of year it is? Yeah, that would be why I carry a blanket with me. Think of the little fleece blankets you tend to use on the couch or something, I have that on my plane ride.
5. Pack your electronics (laptop/tablet/charger/ect) in your carryons - This is kind of basic but so many people leave these items in the bags they have checked that get stored under the plane. Basically, there have been many issues of things going missing or breaking because of being tossed so bring them on the plane with you and store in your purse, carryon bag and so forth. Also, why not keep your charger on your person? There tends to be charging stations at most gates and even outlets on a lot of planes.