A flight attendant shares the 7 biggest mistakes she sees passengers make when packing carry-on suitcases

For the past four years, CiCi has worked as a flight attendant and her job has completely changed the way she packs, she told Insider. On her TikTok account, @cici_inthesky, she shares some of the tips she's learned about flying.

CiCi, which is a moniker, asked Insider to omit her full name and the airline she works for, for privacy reasons. She said that prior to being a flight attendant, she owned multiple companies and worked in real estate. Insider was able to verify CiCi's employment as a flight attendant at a major US airline.

"I have loved it," CiCi told Insider, referring to her flight-attendant career switch. "It's a completely different lifestyle than what I have lived for the last 20-some years."

She shared with Insider seven mistakes she sees passengers make when it comes to packing their suitcases. Take a look at the common — and avoidable — mistakes CiCi sees.

CiCi said she constantly sees passengers who can't pick up their carry-on bags and have to ask for help from other passengers or a flight attendant. But she stressed that lifting suitcases is not part of her job.

CiCi said she doesn't want to risk hurting herself by lifting someone else's bag. As Matador Network reported, airlines can make lifting passengers' suitcases against their policy, so if a flight attendant gets injured while helping with suitcases, they may not receive worker's compensation.

Before boarding a flight, CiCi said passengers should be confident and comfortable lifting their luggage.

While some airlines don't have carry-on weight limits, others like Frontier Airlines and Hawaiian Airlines have rules on how much your suitcase can weigh, according to US News and World Report. So if your bag is overstuffed and weighs too much, depending on the airline, you might have to get it checked at the gate. This can add unwanted time to your travel plans, CiCi said.

CiCi said she constantly sees people who are flying with a roller suitcase, a backpack, and a purse. That's one too many carry-on bags according to airline rules, she said, which results in gate agents often asking passengers to consolidate their belongings into two bags.

According to USA Today, most airlines allow passengers to have one item stored in the overhead bin and one personal item that fits below the seat in front of them.

CiCi said passengers should make sure they're able to fit their belongings into the allotted amount of bags for your airline, noting that some airlines charge extra for carry-on suitcases, which can range anywhere from $10 to $75, Insider previously reported.

CiCi said passengers who need to access their carry-on suitcases can sometimes cause delays in boarding. She tells passengers to pack everything they need for a flight in their personal items.

"People put things that they need on the plane — like their book and their earbuds or whatever they're going to need — inside their suitcase," she said. "And it's not easy to access."

If a passenger has to get inside their suitcase and sift through their belongings during the boarding process, this can block other passengers from their seats and cause delays, CiCi said.

If they wait until midair to get items from their suitcase, turbulence could've shifted the bags in the overhead bin, which might cause them to fall and injure someone.

CiCi said her advice is to make sure all your flight essentials are in your personal item, which will be within reach during the flight.

When you fly, the changing altitudes that an airplane experiences cause gas and air to expand during a flight. This, in turn, can cause leaks in your carry-on from everything from toiletries to water bottles, according to The Points Guy.

CiCi told Insider that in her experience observing passengers' TSA-approved liquids, "people's stuff leaks all over the place," she said. To help, CiCi said she has a few tips.

First, squeeze as much air out of the bottle as possible. This will help prevent expansion, she said.

Perhaps most importantly, she said, choose travel-sized containers wisely. CiCi said she's tried dozens of different travel-sized containers specifically designed not to leak, but the ones she's had the most success with have screw-on caps instead of snap-on tops.

She said she thinks these create a tighter seal, which helps prevent leaking.

CiCi said one of the most important things is to stay hydrated on a flight.

Indeed, the Aerospace Medical Association recommends travelers drink 8 ounces of water each hour they're on an airplane in order to stay hydrated.

And while you can't bring more than 3 ounces of liquids on the plane, you can bring either a frozen water bottle or an empty water bottle you can fill once you're inside the airport terminal, CiCi said. According to the Transportation Security Administration, frozen liquids are allowed through security as long as they're completely frozen.

CiCi said that turbulence during the summer season can get intense. According to Plane and Pilot Magazine, the summer months bring high heat, which causes more convective turbulence in the sky. CiCi said when there's a lot of turbulence, flight attendants are sometimes required to be seated for an entire flight.

If flight attendants can't get up, that means passengers don't get snacks or beverages. Some airlines like Frontier Airlines and Allegiant Air, have ditched the complimentary snack service altogether and only offer drinks and snacks for sale, according to The Points Guy.

CiCi suggests that passengers be prepared with their own snacks. She said beyond fruits like apples and oranges, she also always has a few bags of nuts in her luggage.

If you're flying with just a carry-on, one mistake is packing your heavy items instead of wearing them onboard the plane, CiCi said.

CiCi said she's sometimes shocked to speak to passengers who are traveling far distances with just a carry-on and wearing light airplane attire.

That's not what CiCi does. For instance, on a recent flight to Italy, CiCi said she made sure to wear her bulky rain boots, a sweater, and a jacket — even though she was flying out of hot, humid Florida. She added that this saved her a significant amount of space in her carry-on and allowed her to pack more outfits for her trip.