Planes are going to be crowded. Patience will be tried. Some level of aggravation is all but inevitable. Throw in a seat-kicker, a tipsy stranger and someone who’s blissfully barefoot, and the holiday odyssey becomes a little more challenging.

And this Thanksgiving is poised to be a record-setter for air travel. Industry trade organization Airlines for America expects more than 31 million passengers to fly over the Thanksgiving holiday period — the busiest on record. The Federal Aviation Administration says it might even have to slow down traffic because of staffing shortages in the Northeast.

It’ll all go a little more smoothly if every passenger brings some common courtesy along for the ride, so CNN Travel spoke with experts about the best approaches to airplane etiquette.

The missing ingredient, in many cases, is self-awareness. People tend to get wrapped up in their own journey and forget that there’s a whole planeload of other passengers.

“It’s always kind of mind-blowing to see that because it’s my bag, and my overhead bin, and my seat, and my flight, my connection and, you know, my drink, and it’s very me me me when it comes to just how people behave on an airplane.

“And it’s like, there’s hundreds of you,” said Rich Henderson, who’s been a flight attendant for about a decade. “You’ve got to be aware of your surroundings, you’ve got to be respectful of the people around you.”

It starts with ‘hello’

Be polite to the flight crew greeting you. “It goes a long way when you’re pleasant to the first person you see on the plane,” said Diane Gottsman, an etiquette expert and owner of The Protocol School of Texas.

Andrew Henderson, a flight attendant with more than 20 years of experience, seconds that notion.

“A simple ‘hello’ or ‘thank you’ or acknowledgment of our existence is polite. I think that’s some of the etiquette that’s being lost these days with all the noise-canceling headphones and devices we’re on. We’re all so busy that we forget that humans exist in the world,” said Andrew Henderson. He is married to Rich Henderson and together they run the website and social media accounts Two Guys on a Plane, where “the sass is complimentary.”

About those headphones

Earbuds and noise-canceling headphones are a double-edged sword: great for blocking out the world when it’s intrusive, but not so great for paying attention when it matters.

“We’re there primarily for safety reasons as flight attendants and you know we often joke, but it’s not really a joke, that if there was an emergency situation, half the people would still be on the plane because they have noise-canceling headphones on and they’re in their phones and they’re not paying attention to what’s going on around them,” said Rich Henderson. “And it’s kind of scary to think about.”

Passengers lost in their own world also tend to miss things like beverage service and then get annoyed that they’re skipped.

“If you see a cart, a flight attendant approaching your row, take your headphones off, look up, acknowledge that they’re there so that we don’t have to have challenging situations in the future,” said Andrew Henderson.

But noise canceling devices, which Gottsman called “the universal sign of ‘I don’t want to be bothered,’” obviously come in handy. Neighbor talking your ear off? Put on headphones.

And they’re a savior when babies are crying.

So put them on your ears and be kind.

Kids on planes

“I feel like we really need to give grace to traveling parents because we all know … it’s not the baby’s fault, and it puts the parent in such an uncomfortable situation to see people rolling their eyes,” said Gottsman. “They don’t want the baby to cry any more than we do.”

But kids-gone-wild scenarios are another story. Inattentive parents frequently make lists of the most annoying behaviors on planes.

“The flipside of that is parents — much like in any public space — should be expected to keep an eye on their children,” Gottsman said. “If they’re at a restaurant, if they’re in a grocery store, certainly when they’re in an airplane, for the safety of the child, for the comfort of fellow passengers. You know, be attentive to them kicking the seat in front of them.”

Seat-kicking and other conflicts

Seat-kicking is a frequent passenger complaint, along with armrest-hogging and a laundry list of other grievances.

“I think that we all just have to be a little kinder to each other. If someone’s kicking your seat, you have to be an adult and turn around and speak to the person,” said Andrew Henderson.

These situations require communication to head off frustration before it happens.

“So, if I know I’m a passenger that wants to have the window shade closed the whole flight, I’ll turn to my neighbor and say, ‘Does anyone want the window shade open? It’s my preference to have it closed,’” he said.

And if someone else would like it open, there’s room for negotiation. Maybe they like having it open to see out during takeoff and landing but otherwise are fine having it closed.

Samantha Brown, TV host and travel expert, takes a more unilateral approach to the window shade question: The window seat occupant decides.

“If they would like the shade up, they keep the shade up. The aisle seat person cannot tell the window seat person to put the shade down,” she told CNN emphatically.

Andrew Henderson cautions against such an approach.

“If you just get on and are self-absorbed and ‘It’s my window, I’m going to close it if I want to,’ of course you’re going to start a fight that way,” he said.

Proceed carefully, window seaters.

The rule on armrests

As for armrests, Gottsman said the middle seat gets priority.

“I always say the middle person gets both armrests – gets to choose, let’s put it that way,” she said, adding that the middle seat’s occupant should be able to decide which way they want to lean.

Samantha Brown said the middle seat occupant definitely gets both armrests. “The middle seat — they get anything they want.”

A measured approach to the seat-reclining question

The seat-reclining question certainly cannot be resolved here. To recline or not to recline is a hot-button issue with many travelers on both sides. But bringing courtesy to whichever way you lean is key.

Leaning backwards? “If you’re going to recline your seat back, it’s important to look backwards first and see if somebody’s knees are up against the seat, see if the tray table is down, see if they’ve got food [on the tray table],” said Gottsman.

Rich Henderson believes in reclining, with a caveat.

“As a general rule, I feel like a person should be able to use their seat the way that it’s designed to be used,” he said, adding that “the right thing to do” on a flight that offers meal service is to put your seat forward during that time.

Boozing it up

Some of the most egregious air rage incidents of the past few years have involved alcohol. A passenger who’s had a few drinks at the airport bar and has a few more on the plane may not make the best seatmate or customer. Some end up facing hefty fines.

“I think that it’s important to drink in moderation,” said Gottman. “If you are going to drink, and that’s fine, don’t over imbibe.”

Smelly food, smelly people

There’s no escaping unpleasant odors in tight quarters, so be conscious of what you choose to bring on a plane. Think twice about fish and hard-boiled eggs, for example.

“What’s smelly food to me is not smelly food to someone else, so if you hear people grumbling about your food, maybe the airplane isn’t the best place to eat your fish tacos,” said Andrew Henderson. “Or, know that you have fish tacos and apologize to the group around you that that’s what sounded good to you, ‘I’ll be as quick as I can with eating it.’”

Do your personal grooming at home — do not clip your nails en route to grandma’s house. But do tend to your personal hygiene pre-flight. Smelly passengers – from poor hygiene or too much perfume or cologne, are a common complaint, surveys say.

Smelly feet – or any feet, really

Gottsman urges passengers to choose a pair of shoes that will be comfortable throughout the flight — even if your feet swell.

“It’s not OK to kick off your shoes and take a little nap,” she said. “The nap is fine, but shoes should stay on. And you don’t want to walk up and down the cabin, to the restroom and back, barefooted or in socks.”

Do not, under any circumstance, put your bare feet on another person’s armrest. This happened to Brown in what she called “the most annoying passenger experience I have ever had.”

“Right away I feel no problem just turning around and saying, ‘Please don’t do that,’ but first, you need to document,” she said, showing CNN viewers photos of the offending passenger’s bare feet (yup, both feet) with red toenails.

That also gave the other passenger’s partner time to say, “Uh, you should remove your feet. She’s taking pictures of them.”

Bottom line?

“We could all do a little bit better to be nicer to each other,” said Rich Henderson, “especially in such tight quarters.”