1. Bring your pet on the plane and then act like an animal
Over the years, I've seen a pet on a passenger's lap, a pet tucked into a seatback pocket, and a pet loose in the aisle (I nearly hit one with my beverage cart). All of this is against federal regulations. People tell me how well-behaved their pet is, but they can't follow the rules themselves! Your pet must stay in its carrier while you're on the plane. Yes, even if you've paid a "pet-in-cabin" fee.
2. Shove your bag into the first bin you see and then walk to your seat in the back of the plane
3. Think that because you're on an airplane you're off-duty as a parent
Stop expecting us to have spare diapers, formula, medicine, toys, playing cards, or batteries for DVD players or Game Boys. It's an airplane, not a 7-11. Take your kid to the restroom before you board. Leave the dry cereal and Legos at home and bring snacks and toys for your kids that won't make a horrible mess.
4. Drag on an oversize bag that's too heavy for you to lift by yourself
5. Gripe that you haven't been seated in a roomy exit-row seat
6. Act like you don't know the meaning of the words "under the seat in front of you"
Someday I will be muttering "under the seat in front of you" in the old-age home for flight attendants. What is it that you don't understand? To be clear, items should not be stowed behind your calves, under your feet like a footstool, in the open seat next to you, or in your lap. It's under the seat in front of you. And it applies to everything you carry on board. Items stored carelessly can trip others, or dislodge during takeoff and get lost, or inconvenience others. And while I'm on the topic: Please don't wrap your purse (or umbrella strap) around your ankle to keep from forgetting it. What will happen in an emergency, when every second counts and there's no time to disentangle yourself from your precious bag? Will you drag it ball-and-chain-style down the aisle of a burning plane?
7. Whine about the high price of flying
When I hear people complain about coach airfares, I know they're not keeping up with the news. Fares have rarely been cheaper. In recent years, it's not uncommon for you to be able to cross the continent for under $130 each way, with a maximum of one layover. It's a bargain! At that price, you're barely paying for the fuel to get your body there—never mind the cost of shipping your 50 pounds of gear. You're already on the gravy plane. People point to first class ticket holders and want to know why they don't get the same treatment. Wake up folks: You're getting a great deal. If you want even more, pay more!