The 20 Worst Mistakes You Can Make at the Airport

Not only will you get access to things like free seat selection (and the ability to change your seat), you'll save time when you arrive at the airport. If you're travelling without checked bags, you'll breeze right through the check-in process. Why stand in line when you don't have to?

Plus, improve your trip even more with these 15 easy ways to gain airport lounge access.

You might be excited to jet off to your destination, but before you leave home, check the status of your flight. There's no sense driving all the way to the airport only to discover your flight has been delayed for hours or worse, cancelled. If you're forgetful, sign up for email or text notifications. And if you do get delayed, here is what you can expect for compensation.

It's not just the weather at home that can throw your holiday plans into a tailspin. Bad weather at your destination or along your route can wreak havoc with your flights. Check the forecasts and if it looks like there may be delays, be prepared with extra snacks and things for your kids to do. Even if your departing flight is on time, get to the airport early, to deal with any re-routing issues that may come up.

See more expert flying tips for winter weather.

Carrying a refillable water bottle is good for the environment and is something you should always travel with. It'll also save you money because buying water in the terminal is one of the biggest airport ripoffs that you should avoid. Make sure the bottle is empty before security and then fill up on the other side.

Don't wear heavy winter clothes to the airport if you're flying somewhere tropical. You'll only burden yourself with a bunch of stuff that takes up valuable room and you won't use anyway. Either pile on layers of clothes that you're taking anyway or get a ride to the airport and send your heavy clothes home.

Additionally, don't dress for the beach when you fly. It can get cold on the plane, especially near the emergency exits. There's also a safety issue: you want to be wearing proper clothes and good shoes in case there's an emergency and you have to exit the plane quickly.

A lot of people leave arriving at the airport until the last minute. But the earlier you arrive, the smoother things will go if something goes wrong. You'll have plenty of time to resolve whatever the problem is. Plus, having an hour or two buffer means that you beat the crowds, can relax while going through security, take time to do some duty-free window shopping or just kick back and read while enjoying a hot cuppa.

Don't wait until you get to the airport to pay for a second bag. If you really think you need to bring more stuff (you don't), you can save money by paying for a second checked-in bag online. And make sure you weigh your bags at home, so you're not hit with overweight fees. Also, avoid these packing mistakes.

Waiting until you get to the airport to buy your snacks means you'll likely pay much more and be tempted to eat junk. Plan ahead and bring your own snacks but be sure to include healthy stuff like fruit. If you're travelling to a foreign country make sure you consume all fruit and veggies before arrival as many nations restrict the importation of fresh food items.

You really shouldn't buy anything at the airport unless you really need to. Plan ahead, buy before you leave. If you're tempted to buy something at duty-free, check the prices on your smartphone. Many products aren't really a deal at all.

Many countries require additional paperwork when travelling with children — especially if only one parent is accompanying the child. Make sure you have all the required documentation well in advance of your flight, or you could be turned away. You can find more information about what you'll need on the Government of Canada's website.

If you're flying on a one-way ticket to another country, be prepared to show proof of an outward-bound ticket. Some airlines will stop you from boarding if you can't prove you're going to leave your destination before your visa expires. The reason is simple: if a passenger is refused entry into the destination country, the airline is responsible for flying that person home. There are ways around this: you can buy another ticket and then cancel it (usually within 24 hours) or buy a dirt cheap bus/train ticket online.

It happens more often than you might think: leaving your passport at home. And because you're showing your passport at the airport or using it to fill out forms, there's the chance that you might put it down for a second and then walk away. Know where it is at all times and quadruple check that you have it before you leave the house.

When returning home, make it a smooth process by avoiding these ways to get flagged at customs.

Nothing slows down the lines at security like those people who seem to be clueless about how to travel. You know the ones: standing there, searching through their pockets and bags looking for their boarding pass or passport that they just had. Always keep your documents in your hand or in an easy to reach pocket.

You'd think that everyone would know the rules about bringing liquids on a plane. But judging from the waste bins in security, you'd be wrong. It's quite simple: small containers of 100ml or less, packed in a clear, resealable plastic bag. Packing your liquids wisely is just one way to get through security as fast as possible. If you're still not sure of the rules, head over to the CATSA website.

It's amazing how many people reach the security line and have no clue as to what to do. This is one of the main reasons for long queues. If you're unfamiliar with the rules, educate yourself! In addition to always have your passport and boarding pass in hand, don't forget that your electronic devices need to be charged so they turn on and your laptop must be removed from its bag.

Another way to slow things down at security is to pack restricted items in your carry-on. It's obvious that you can't bring big bottles of shampoo, a pot of grandma's soup or a hunting knife on board. But there are many other items that should be packed in your checked bag or just left at home. Read the rules before you leave the house.

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Avoid wearing metal when you're going through security. It's easy enough to whip off your shoes and a belt, but don't forget to take off your jewellery before you reach security. If you must bring jewellery, don't bring the good stuff. Pack some expensive-looking jewellery that doesn't cost much. Also, don't forget to take out studs and piercings in advance; otherwise you'll set off alarms and slow everyone down.

Restaurants at most airports are expensive. If you think you're going to be hungry while waiting for your flight, be sure to pack some food at home. Stay away from anything with liquids, as it'll be confiscated by security. But a few granola bars can tide you over until your destination. Another option is to eat in one of the airport lounges. Even if you don't have status, there are still some ways you can gain access to the lounge.

Smartphones and tablets are great for travelling. You can load them up with books, games, movies and music. But remember that not everyone wants to hear you battle Zog the Destroyer or listen to your ultimate mix of '60s bubblegum music. Be sure to carry headphones or earbuds with you. If you forgot, ask at the gate if they might have a spare pair. But whatever you do, don't buy a pair at duty-free!

Unless you want to get hauled off by security or the police, don't make jokes. Seriously. DON'T.

SEE ALSO: 20 of the worst airport experiences you can have in the whole world.