Flight attendants travel for a living so when it comes to packing for a trip ”• whether it’s for a few days, a longer stay or an unexpected reroute ”• they’ve learned a few go-to tips.

HuffPost chatted with four flight attendants to get the lowdown on the items they never forget to pack, the ways they pack efficiently and the pet peeves they have with passengers’ packing habits. Spoiler alert: The way you pack might be causing a lot of disruption while boarding.

Check out their bits of advice below.

What They Pack

Kelly Kincaid, a flight attendant for a major airline and the creator of “Jetlagged Comic,” always travels with a pair of flip-flops, no matter the weather at her destination.

“I wear them in my hotel room and in the shower because, well, yuck!” she told HuffPost via email. “I got a plantar wart on the bottom of my foot when I first started flying, and I believe it was from using the hotel showers without a barrier.”

She noted that they’re usually lightweight and easy to pack, meaning you’ll still have plenty of room for your other belongings.

As an avid traveller, Taresha Ferguson, who vlogs about her life as a flight attendant for a major airline on her YouTube channel “Traveling with Tee,” never flies without moisturizer.

“When you fly a lot your skin becomes drier than usual due to the cabin pressure and constantly changing climates,” she said via email. “Moisturizing is essential if that’s the case, or your skin will age way faster than you!”

She also brings a portable charger since flights aren’t guaranteed to have outlets available.

Ashley Smith, the flight attendant behind the YouTube channel “AshleySmithTV,” has four essentials in her bag: an umbrella, a little black dress, a swimsuit and “of course,” sunscreen. In other words, if she gets rerouted and ends up in a location she didn’t even know about a few hours before, she’s always prepared to go to the beach, go out for a night or get around if it’s raining.

To keep her cords packed away and organized, Stella Connolly, a New York-based flight attendant who “documents her life at 38,000 feet” on her YouTube channel “Fly with Stella,” swears by gear ties.

“I buy them in bright colours so I can find my chargers faster,” she said via email.

How They Pack

Depending on the size of your luggage (and whether you prefer only taking a carry-on or checking in a bag), figuring out how to pack everything can be like a game of Tetris. Ferguson has a system for her belongings.

“My luggage is usually set up by having my shoes on the bottom of my luggage,” she said. “Then complete outfits, by day, rolled up (so they never get wrinkled) on top of the shoes. Lastly, my toiletries bag with all of my makeup and soaps tucked off in its own corner. The key to packing efficiently is only packing what you need, clothes-wise.”

She recommended packing outfits with similar colours so you only have to pack two pairs of shoes, max.

Smith uses “shoe bags” when flying, by either storing her shoes in the packaging they came in (if she ordered them online) or reusing plastic bags.

If you’re a chronic over-packer, Kincaid recommends abandoning the idea of wearing a new outfit every day on your travels so you can re-wear the same clothes two or three times.

“Obviously, I wear new undies and socks every day, but if I’m on a three-day trip, I’ll wear the same thing on my layovers,” she said. “I always choose a simple outfit I can layer.”

It’s also helpful to be strategic in what you wear to the airport. Connolly suggested wearing your heaviest things instead of packing them (think jackets and shoes). Wearing layers and wrapping sweaters around your waist can also allow for extra room in your luggage.

What You Shouldn’t Do

It’s no surprise that flight attendants have a few pet peeves when it comes to their passengers. One of Ferguson’s biggest issues is with guests who pack the items they know they’ll want during the flight in their bag that’s stowed away in the overhead bin instead of in their personal item under the seat in front of them. This can cause delays and disruptions, especially when everyone is trying to board.

“This wouldn’t be a problem if you removed your items in the boarding area prior to stepping foot on the aircraft,” she said. “It’s a problem when these passengers hold up the boarding process on the aircraft as they’re taking their items out of the roller board [luggage] before they stow it. Even stowing your luggage and then remembering you need something any time until we’re in the air is a huge disruption as we only have a limited amount of time to push back from the gate and take off to remain on time.”

If you don’t mind checking a bag, be sure to pack your overnight essentials in one of your carry-on bags, Smith said, in case you and your luggage aren’t reunited right away.

“It’s not a rare thing for your luggage to be misplaced,” she said.

It’s even better if they fit in your personal item since sometimes even if you get to the gate with a carry-on, it has to be checked in, anyway.

And as Ferguson pointed out, checked bags can sometimes give you the feeling that you should pack as much as possible. She recommended leaving a bit of room in case you buy or collect anything at your destination you want to bring home.

“That way you can avoid coming home with extra luggage to carry,” she said.

And As A Bonus

In the market for a new carry-on? Connolly advised staying away from black luggage so it’s easier to find your bags among the many others surrounding it. It’s also helpful to have any checked luggage easy to spot on the baggage claim carousel.

“Buy luggage that stands out so your bag won’t get confused with everyone else’s,” she said.