1) RESEARCH. I didn't realize that there will still people who didn't realize that you can't bring liquids on a plane, but they exist, and they hold up the TSA security line like you wouldn't believe. You can't bring anything above 3 oz, which includes the coffee and the water bottle you bought outside of security.
Here's a hint: I never put my small toiletries in that damn little quart bag. I hide them strategically throughout my bag and I've had my bag searched for them maybe twice (after flying twice a week for the last 18 months). If they do catch them and open my bag (again, very rare occurrence), I simply play the "oh I packed in a hurry" card.
2) Flying with Children? Don't. Make people fly to you. Kidding, of course, but hear my facetious rationale on this one. I don't even say it because crying children annoy me, I say it because I feel bad for the parents who have to collapse a giant stroller, hold a baby and 2348723 bags filled with things to keep their toddler's mind off of her throbbing ears, all while managing an apologetic smile to the person next in line to get on the plane. I've watched single parents pass their children to complete strangers just so they can wrangle the ridiculous amount of luggage required to travel with a child or children (not blaming the parents here, I'd do the same thing). Clearly this is tongue-in-cheek, as I understand it's often impossible not to fly with children...but seriously. Think about it.
Also, if you don't have kids, and you see people with children who are using that leash thing, don't judge them. I'm not even a parent and I can totally understand why people use these. Also, try not to judge parents of screaming children. It's not their fault and let's face it, if we could all scream and cry while flying we probably would.
Picture from http://findcheapairfare.com
3) Do you have a disability or have to travel with children? BE OBNOXIOUS. You know those people that inch their way up to the gate around half an hour before boarding? Those are frequent travelers. They can board first, meaning they are privy to all of the overhead space before everyone else boards.
HOWEVER, if you have children under the age of 5 or "need extra time down the jetway" (for example, if you are elderly or have a disability) you can board before all of these people. So here is my hint to you as a frequent traveler: be obnoxious and force your way to the front of these gate zombies. Often as soon as the gate agent starts announcing, the zombies crowd the area making it impossible for you to get through, especially if you have children or have a tough time walking. Grab a seat close to the gate entrance and when you get to the half-hour mark do not be afraid to charge your way through us douchey business travelers.
Picture from http://www.spinal-injury.net.
4) If you are in Zone/Seating Area 3-5, the last tip does not apply to you. Stay back and wait until you're called. We all had to deal with it at one point and you just make things more difficult.
5) Do NOT put your seat all the way back, unless you want to be an intolerable douche and want me to push on your seat the entire time, because that's what I do. Conversely, don't force your legs up against the seat so that the person in front cannot push their seat back. Incredibly douchey.
6) If you sit in the back of the plane, do NOT put your luggage in the front of the plane. Again, don't be an intolerable douche. People in the bulkhead seat have to put all of their things in the overhead compartment
7) Related to #6, if you are in a bulkhead seat, put all of your luggage in the overhead compartment. You can't hold your purse, you can't put it behind your feet. It all has to go in the overhead compartment. It's obnoxious but if you asked for more legroom, this is what you get.
8) Don't Hold up Traffic in the Airport. It's the same as driving - stick to the right. Don't drive down the middle, or stop in the middle of the lane. Go with the flow and we'll all get where we're going.
I hope this helps those of you who may not travel as frequently as I do. Enjoy! :)