(Bloomberg) At the age of 21, Lexie Alford has already visited all 196 countries in the world. That makes her the new Guinness World Record holder for youngest person to travel to every country, by three years. (There are 195 states widely recognized as countries, plus Taiwan.)

With a family that ran a travel agency, Alford traveled widely as a child—by the age of 18 she’d already hit 72 countries. That’s when she decided to sprint for the world record, self-funding her trips via work as a travel consultant and some sporadic sponsorships. She documents her experiences on her blog and is now working on a book.

Alford, who lives in Nevada City, Calif., logs from 200,000 to 250,000 miles in the air each year, though she frequently takes trains and buses as well. Her favorite airline is Delta, because of its partnership with American Express Platinum, a lucrative points-earning program. “They also have the most reliable airport lounges in the world, just as far as the Wi-Fi and the food,” she says.

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Here are Alford’s tips from a lifetime of globe-trotting.

You can—and should—hold two passports from the same country, simultaneously.

Having two passports is essential if you’re traveling to some of the lesser-known places, or where visas take a long time to obtain: the Middle East or West Africa, for example. It’s for when you have conflicting travel plans that are related to obtaining a visa. If you go to the passport office and map out how it’s impossible for you to follow through on your travel plans—especially if they’re related to business—with just one passport, they’ll issue another one. Say you’re going to Russia and need to send it to the embassy; that will take six weeks. But perhaps you’re going to Indonesia next week. You just need to show written evidence of your conflicting flights, with your name on the reservation. And remember: You can book refundable tickets as proof of travel, show them at the passport office, and then cancel them later. Then you’ll have one handy for any future travel traffic jams.

If you’re traveling to a new county, there’s one email you should always send before you leave.

Email your hotel before you arrive and ask what the average price is for a taxi from the airport to the hotel. Sending this simple email has saved me hundreds of dollars over the years, because I’ve avoided being taken advantage of by taxi drivers with inflated prices or fixed meters. Taxi drivers can be merciless as far as screwing you over, so you need to be very sure on exactly how much it’s going to cost and how long it’s going to take to go from A to B. If you get to the hotel and the meter is unbelievably high, refuse to pay for it. Go inside the hotel and ask for help. And if that doesn’t work, tell them to call the police. If you say that, the driver will give up. I’ve done that in Angola a few times, and in Samoa. And I just did that in Guinea-Bissau.

Image: Pixabay

Your carry-on allowance is probably more generous than you think.

I only travel with a carry-on. Some of the airlines might be more strict, though, and will weigh it. I remember being in Zakynthos, Greece, and there was a very grumpy check-in lady who weighed both my carry-on and my backpack. I’m always way overweight because I have my laptop, my camera, and my drone. It was 5 kilos (11 pounds) over. So I just put on as many of my clothes as possible. Then I went to a souvenir shop across the way and bought a cheap duffle bag and put stuff in there, too. You’re able to bring the equivalent of a shopping bag along with your carry-on. So now I carry a collapsible, lightweight duffle bag from Baggallini for the worst-case scenario. Just be very discreet when you walk up to the counter, and don’t offer to let them look at your luggage.

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Skyscanner should be your default flight search engine.

Skyscanner is definitely the best for booking last-minute stuff. It’s the most reliable, and it shows many different options: the fastest route, the cheapest route. You can select how many stops you want to make, and it’s so user-friendly that even someone who’s never looked at it before would be able to navigate the site. It also has an alternative for greener choices—for example: “This flight emits 32% less CO₂ than average for your search.” If you’d like to be environmentally conscious when you travel, this helps.

One piece of clothing will prove more useful than everything else.

For women it’s a lightweight, long-sleeve button-down. It can go as a light jacket if you need one, and it’s easy to layer on top of other shirts. And if you’re wearing shorts and feeling uncomfortable in a more conservative country, you can wrap it around your waist to cover the back of your thighs.

On longer trips, follow the three-day rule.

I usually prioritize having at least three days in the same city, in the same hotel room, a week into each of my long trips. There’s a few reasons for this. For one, you’re going to need to do some laundry, and that could take three days—one to find the laundromat, the second to leave it with them, as it might not be open when you find it, and the third to pick it up. And if you’re traveling through a lot of places really quickly, it’s easy to get burned out. Having a three-day stop every week or so gives you the chance to get grounded. People rarely think about having to pack and unpack as being exhausting, but it really is.

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Want a souvenir from each place you’ve visited? Here’s a lightweight idea.

I’ve collected a piece of the currency every time. We all end up with small denominations of bills and now have this huge wall, an entire wall, filled up with currency from each country. The Hong Kong dollar has really interesting colors, and the Costa Rican currency has the most beautiful depictions of local wildlife.