A lot of people are frequent flyers these days, but their knowledge of air travel still can’t compare with the level that flight attendants possess. This is especially clear when crew members travel as passengers themselves.

“Working as a flight attendant changes your perspective on a lot of things,” Francesco Lentini, a flight attendant with a major U.S. carrier, told HuffPost. “You learn that many people are traveling for different reasons, whether it be vacation or a funeral, so you learn to be empathetic. You also realize that some people can be inconsiderate and are not thinking about their fellow passengers.”

To combat that lack of consideration and offer guidance for air travelers, HuffPost asked Lentini and other flight attendants what behaviors they always avoid when they fly as passengers.

“When I’m a passenger on a flight, you’ll never catch me taking off my shoes, walking barefoot, or casually putting my feet all over the walls and seats,” said Jay Robert, a former flight attendant and the founder of A Fly Guy Travels.

In addition to the lack of social decorum, there are also hygiene considerations.

“Having witnessed what goes on behind the scenes, I’m not about to expose my bare skin to the floors of an aircraft,” Robert noted. “I’ve seen the effort the crew puts into ‘cleaning’ the toilets on flights, and that damp bathroom floor isn’t damp from sink water.”

He added: “Airplane carpets are typically spot-cleaned, if cleaned at all during the daily rotations. I’ve encountered every imaginable human fluid stain on those carpets. The goal for aircraft cleaners is often just to mask the smell; they don’t have the time, especially when the plane is in operation, to thoroughly clean the carpet.”

“As a passenger, I would never stand in the aircraft galley for a lengthy period of time,” Lentini said. “This is the flight attendant’s workspace where we work and eat. Last thing we want is to have a passenger doing yoga poses in our faces while we are having our lunch.”

Robert similarly emphasized the limited breaks that the cabin crew might get between and during flights.

“During flights on the London-to-Dubai route, our free time in uniform was a mere 15 minutes within a 15-hour time frame, usually spent hastily grabbing a meal that often got interrupted by someone needing assistance,” he explained.

“As a passenger now, I make a conscious effort not to intrude into the crew’s spaces, ensuring they can have a peaceful meal break. Treating the aircraft as the cabin crew’s office is crucial. I wouldn’t barge into a restaurant or hotel and sit in the employee break room to watch them eat, so I extend the same respect to the staff in the sky. It’s a shared space, and recognizing and respecting the limited space available is key.”

“When I am on a plane as a passenger, one thing I would never do is ring the call light button unless it’s an emergency,” said Christa Treat, a flight attendant with a major U.S. airline. “Most people think that button is for extra drinks and snacks. But in reality, call lights should be saved for emergencies. Majority of the time, flight attendants never sit down and are constantly running the entire time doing things, so ringing the call light to ask for another drink as a passenger is something I would never do.”

She noted that flight attendants frequently come through the cabin to do safety checks, so if you need another drink, you can ask then. Or if the seat belt light is off, you’re welcome to go to the galley to make a request.

“Get up, stretch your legs and walk to the back to say hello,” said Heather Poole, a flight attendant and the author of “Cruising Attitude: Tales of Crashpads, Crew Drama, and Crazy Passengers at 35,000 Feet.”

“I would never hand trash to the flight attendant as I’m boarding the airplane — which happens quite often,” Lentini said. “People come on the plane with their trash from the terminal and give it to the flight attendant to throw away.”

Flight attendants have to do important preflight checks and keep the boarding process running smoothly as passengers stow their bags and find their seats. So try to dispose of your trash in one of the receptacles in the airport before boarding.

Similarly, try to do your business before boarding and takeoff as well.

“When I’m a passenger on an airplane, I would never use the aircraft lavatory during the boarding process,” Lentini said. “There are dozens of restrooms in the terminal to use. Using the lavatory during boarding can delay departure because then passengers are going against the flow of traffic to get back to their seat.”

Many travelers understandably prefer to stick to carry-on luggage when they travel, but you still need to adhere to the size and weight restrictions.

“I want passengers to know if you can’t lift your bag in the overhead bins, chances are I can’t either,” Treat said. “We are glad to check your bag and help get it to your final destination, but there’s no need for either of us to get a shoulder injury just because you want your bag above you. We’ll check it for free!”

If you want a tasty, filling meal on a flight day, don’t assume that the airline will provide that for you on the plane. Unless you’re in a special premium cabin, you’re mostly on your own.

“I don’t depend on an airline to take care of me,” Poole said. “I buy water in the terminal and make sure to bring food from home, or I buy something to eat before the flight. Travel is more enjoyable when you take care of yourself. Airplane food is like astronaut food. Not worth getting upset over.“

“What has changed the most for me since becoming a flight attendant is how I prepare myself before boarding the aircraft,” said Sif Björnsdóttir, a senior cabin crew member and deputy manager of cabin crew training at the Icelandic airline Play. “I have everything I need in my seat ready to go and everything else goes in my in flight bag so that when I board, it takes me seconds to get to my seat.”

She emphasized the importance of getting organized before the boarding process.

“If there is one passenger taking too much time to get things from their bag, everyone else has to wait for that person to get in their seat,” she said.

“Working as a flight attendant will change your perspective the same way working as a waiter changes your dining experience, or how working in retail changes how you treat anyone who works in sales,” Poole said. “You make eye contact, you say hello, please, and thank you, and you treat workers with respect. You have patience, and you know when something goes wrong there’s only so much a person can do. You know a flight attendant can’t blink and, poof, magically create more baggage space or fix a broken plane.”

Poole and other flight attendants who spoke to HuffPost emphasized that their primary job is ensuring safety. Although they do serve food and drinks, flight attendant training focuses on skills like evacuating airplanes, applying first-aid techniques, using emergency equipment, putting out fires, handling dangerous items and surviving in the event of a water landing.

“Obviously as a flight attendant, I want everyone to be comfortable and hydrated and have a great flight, but it’s our job to keep everyone safe first,” Treat said. “That’s why we are so rigid about the rules. Our job is to get you from point A to point B safely.”

Flight crews in the U.S. also typically aren’t paid until the airplane doors shut, which means their efforts during the boarding and deplaning process — and the hour they’re required to be at the airport before the flight and the time between consecutive flights — are not compensated. During long workdays involving many unpaid hours, kindness from passengers can really go a long way.

“A flight attendant has no control over why the Wi-Fi is not working, or an aircraft maintenance issue, or whether or not you will make your connection ― and no, we can’t call your next flight and tell them to hold the plane,” Lentini said. “But at the end of the day, a flight attendant will bend over backwards for you as long as you’re kind and treat them with respect.”