Flying can be remarkably stressful, especially if you don’t prepare beforehand.

If you make a few simple mistakes, you might find yourself booking an additional flight. According to an American Airlines executive, airport screening delays caused more than 70,000 of the airline’s customers to miss their flights in 2016.

Of course, the stress doesn’t end when you’ve boarded your plane. We decided to talk to a few flight attendants and travel experts to identify a few of the most common mistakes that travelers make—and how to fly a bit more intelligently on your next trip.

1. Give yourself plenty of time for each task.

All of our experts agreed that the most common mistake was a simple lack of preparation. Flight attendant Steffanie Rivers told FashionBeans that travelers frequently underestimate the amount of time that they’ll spend at the airport, and that starts days before the actual flight date.

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“I like to think of flying as sort of like planning a wedding,” Rivers explains. “If you want a great June wedding, there are ‘must do’s’ that happen a month before, two months before, and so on.”

That means remembering to check in as soon as your airline allows you to do so. This crucial step will improve your boarding position and give you more seating options—provided that you’re able to check in within minutes of the airline’s official online check-in time, typically 24-30 hours before the flight departure.

After you’ve handled that important step, make your plans for your flight, but don’t be overly optimistic.

“For an 8:00 a.m. flight, passengers need to be in the security line no later than 7:00. That might mean you have to get up at 4:00 to leave at 5:00 and arrive at the airport at 6:00, allowing yourself enough time to park.”

Rivers says that a successful flight is all about budgeting time properly. Roni Faida, a former airline worker who now runs a travel blog, agrees.

“Most airlines have cut-off times for checking bags, and many passengers don’t know this. When they get to the counter, they’re often surprised that they’ve missed the cut-off…If you’re checking a bag, get to the airport at least two hours before departure time (for domestic flights) and three hours (for international flights).”

2. Only pack what you absolutely need, especially with your carry-on luggage.

Many travelers over-prepare, which can lead to unnecessary stress.

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“Only bring what you need,” says Rivers. “Only bring luggage that you can handle, carry, control, lift into the overhead bin yourself. If you can’t do that, either reconsider bringing it or check your luggage. Don’t expect flight attendants to lift, carry, pull, your luggage.”

With that said, don’t leave off anything that’s essential.

“Prescription medication should never be packed in a checked bag,” Faida says. “What happens if the bag is lost or doesn’t arrive at the same time as the passenger? Any type of [necessary] medication should always be in a carry-on bag.”

But what about TSA regulations? Don’t worry, we’re getting there.

3. Understand what TSA regulations ban…and what isn’t banned.

This might sound like a no-brainer, but TSA screening procedures can easily change your travel plans.

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Brian Karimzad, analyst at travel site, has flown over 2 million miles. He says that he regularly sees absentminded mistakes turn into huge ordeals for travelers.

“Don’t leave that bottle of water behind in your bag,” Karimzad suggests. “If the TSA finds it, your bag will be subjected to extra screening, which means more time waiting around for you.”

Be ready for the screening to take some time, but do what you can to limit the inconvenience. Avoid wearing clothing with a large amount of metal. Fully empty your pockets before going through metal detectors, listen to the agents, and you should be able to avoid a more intensive screening. While you’re waiting in line, study a map of the airport so that you know where to go.

“The TSA security process can be intimidating, and if passengers are unfamiliar with the airport, they’re an emotional mess by the time they step onto the airplanes,” Rivers says. “That is, if they make their flights.”

TSA security measures change on occasion. In late June 2017, Department of Homeland Security (DHS) Secretary John Kelly announced new security requirements for nearly 280 airports, including new regulations requiring passengers to place all electronics larger than a cell phone into X-ray screening bins. If you’re not aware of the regulations, you can’t plan ahead, and you’ll drag down the line.

It’s equally important to know what not to do. For instance, parents don’t need to have children under the age of 12 remove their shoes; skipping this step could save you valuable minutes. The good news is that you can read up on TSA regulations on the DHS website.

4. Know how to deal with a flight delay or cancellation.

Flight delays happen. According to the Bureau of Transportation Statistics (BTS), about 20 percent of flights were delayed in 2017, while 1.45 percent were canceled outright.

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Have a plan in place for this eventuality. Most travelers head to their airline’s support counter to reschedule their travel plans. According to Karimzad, that’s a mistake.

“Don’t wait in line when you need help,” he says. “When your flight is cancelled or delayed, phone agents can do as much as the agents at the airport, so plug in your phone and get help faster. You can also login to the website or app of your airline and rebook in many cases.”

Be polite and understand your airline’s policies. Most won’t be obligated to find you an alternate flight, but if you ask nicely, they’ll be happy to accommodate you.

Don’t forget about the other stuff. Keep your hotel and car rental reservations on hand in case you need to make sudden changes. When you’re traveling internationally, consider paying for flight cancellation coverage on your travel insurance; it’s often fairly inexpensive, and it can give you tremendous peace of mind.

5. Be prepared for your time in the airport.

While you’re waiting, you might need to plug in your laptop to get some work done. Don’t assume that you’ll be able to find a power outlet, especially if you’re traveling during peak flight times.

“Carry a small power adapter with two or three slots in it,” Karimzad says. “That way, if someone is using an airport power outlet, you can plug in your adapter and share the power.” Crisis averted

If you planned your trip properly, you might have quite a bit of downtime, but make sure that you know how much time you’ll need to get to your gate. That’s especially important if you’re planning on using a few low-fare airlines to get to your destination.

“Typically, passengers don’t consider the [correct] amount of time needed to get from one airline to the next, because they’ll have to collect their luggage and recheck it,” says Dr. Cacinda Maloney, travel writer at “Also, many international flights have a one-hour cutoff to get the luggage to the plane.”

To stay safe, give yourself plenty of time between connecting flights. While you’re waiting, you might consider picking up a few duty-free items or switching your currency. Go ahead and pick up the souvenirs, but resist the urge to get the foreign cash.

“Don’t change your money at the airport,” Karimzad suggests. “It’s often an inflated exchange rate. Better to carry a credit card with no foreign transaction fees for purchases—or withdraw money from a bank ATM. Credit cards get some of the best exchange rates available.”

That brings us to another important point…

6. When traveling internationally, research your trip thoroughly.

International travel presents an entirely new set of challenges. Know how different countries and airports regulate flights. For example, some airports can’t process digital tickets easily, so a paper ticket can allow for a smoother experience.

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Again, you’ll need to give yourself plenty of time, but that’s not easy without research. Even experienced travelers forget to account for some of the nuances of international travel.

Andy Abramson, the 2015 Business Traveler of the Year for Business Traveler Magazine, spends more than 200 days per year traveling. He told us about a recent trip through the Lisbon airport.

“I was flying to London and spent a bit more time in the lounge and went to go to the gate, forgetting I still had to clear immigration in Lisbon,” Abramson says. “Even though my walk to the gate would be all of 5 minutes, the passport control requirement added time—too much time. Given it was a Saturday, in the summer, I had a very long line.”

Abramson wasn’t particularly worried, as he has a chip-enabled passport that allows him to move through immigration quickly. However, he’d forgotten that he hadn’t entered the European Union in Portugal, and as a result, the chip didn’t register.

“Lesson learned: Always be at the gate early,” Abramson says. “And know what you have to do to get there.”