Being late to the airport, getting stuck in a long security line, being told your bag’s too heavy to carry on — these are all preventable mistakes that can lead to great stress, which, as we all know, is a recipe for inconsiderate behavior. So step one for being a courteous flier is to not make any unforced flying errors: Prepare for your flight. “That includes arriving early, not packing too much, and packing a positive mental attitude,“ says Whitmore. To paraphrase "Annie”: ‘You’re never fully packed without a smile.’” WATCH: Our Guilty Travel Pleasure — Videos of People Getting Kicked Off Flights

This may seem like common sense, but Whitmore says passengers who bring large carry-ons are the number one pet peeve of flight attendants. “Some people try to get on the plane with bags as big as a Mercedes-Benz, and then they ask the flight attendant to stow it for them,” Whitmore says. That holds up the boarding process and the disembarking process (when you try to get that gigantic suitcase from the overhead bin), not to mention the stress it puts on the people behind you. Whitmore has a simple rule: “If you can’t lift it, check it.” Related: How Not to Be Annoying on a Plane

But, for Pete’s sake, help someone with his or her bag if you canYes, that elderly woman or the mom holding two babies probably should have packed lighter, but that’s in the past. In the here and now, she’s having serious trouble getting her bag from the overhead bin — putting herself and others at risk of injury. Now’s not the time to be the carry-on police: Step up and help the person out. “It’s just the kind thing to do,” says Whitmore, “instead of just sitting there watching them struggle.” Related: Don’t Be an In-Flight Jerk: How to Win Friends and Influence Flight Attendants

We all know that with airlines decreasing legroom in economy, reclining has become a hot-button battle. Whitmore is in the “pro-recliner” camp, but she recommends you do it carefully. “Do it slowly and take a peek behind you because that person might have a laptop or food on their tray table,” she says. And when food service begins, bring your seat back up so the person behind you can eat without the tray table jabbing him or her in the gut. Related: Things You Should Never Say to a Flight Attendant (Unless You Want to Make Her Mad)

When you have three seats next to each other, who gets what armrest? To Whitmore, the answer is easy. “The person sitting in the aisle has the luxury of getting up first. The person by the window has the best view.” So, she thinks the person stuck in the middle should have domain over both of the two middle armrests. “Nobody knows that rule,” a surprised Whitmore says. We’re shocked, too.

Don’t play your music / video games / movies on your device without headphones. And try not to stink up the entire cabin with food you bring on board. “Be aware that there are certain foods that permeate the cabin,” Whitmore says. “So when you bring on that big Philly cheesesteak with onions and green peppers, that’s gonna make the plane smell.” But Whitmore, who’s been known to bring food aboard airplanes herself, realizes that this can’t always be helped. In those cases, she says: “I apologize to the people behind me.”

There are times when we look forward to a flight where we can read a book, watch a movie, or sleep. And Whitmore sees no reason to let the talkative stranger sitting next to you derail your plans. “Be polite, be diplomatic, but be honest,” she says. “If you’re trying to get some work done or sleep, say, ‘It’s been such a pleasure speaking with you, but I’ve got to get some work done.’” Or you can choose a policy of nonengagement. “Sometimes if I don’t want to talk, I’ll put my earphones on immediately after I sit down,” Whitmore says. “That sends a clear signal.”

It’s strange how people will patiently endure a 10-hour flight, yet a 10-minute wait to get off the plane seems like torture. Whitmore suggests not creating a stampede for the door. “Allow people seated in front of you to disembark first (yes, even if you have no carry-ons and everyone else in front of you is fumbling in the overhead bin).” If you’re late for a connection, tell the flight attendant; he or she can help make sure you jump the line to get off the plane.

What if you encounter a rude fellow passenger who obviously didn’t read these rules? Don’t be too quick to confront. “If you have an issue with a passenger, it’s best to take it up with the flight attendant first versus taking matters into your own hands,” Whitmore says.

There’s probably not much that parents can do about a screaming baby, but sometimes parents forget to mind older children. Whitmore remembers a particularly painful flight to Las Vegas where a mother refused to deal with her out-of-control kids. “[Her children] were jumping on seats, screaming, yelling, just being like animals. And [the mother] was zoning out completely,” Whitmore says, noting that the rest of the passengers hated this woman. Don’t let it happen to you; mind your kids. And for Pete’s sake, don’t change your baby’s diaper on the seat. “Most lavatories have changing tables,” Whitmore says. Use them. Let Yahoo Travel inspire you every day. Hang out with us on Facebook, Twitter, Instagram, and Pinterest. And check out Yahoo Travel’s original video series A Broad Abroad.