I've been working and traveling abroad for 2 years and I never plan a trip in advance. Here are my best tips for booking travel at the last minute.

If you're flying in the US, use Southwest

Southwest mainly flies within the US and neighboring countries, such as Mexico.

Southwest's Low Fare Calendar is great for last-minute travel. Let's say you see a flight from LA to Chicago for $99. A few minutes later, it goes up to $150 — but don't panic. Just keep refreshing your browser every few minutes — and also try your search from an incognito window. Clearing your cache and cookies will help, too.

And, 9.9 times out of 10, a flight will become available again for the $99. If not, you can get the $150 one in the meantime and when you see the $99 pop up again, exchange it for that for no fee. You'll get the remaining $51 as a flight credit that's good for a year.

Also, if you don't check into your flight and suddenly cannot take it, you can cancel it even up to 10 minutes beforehand. And, yes, you'll get a flight credit to use within a year. You can also get a monetary refund if you cancel a flight within 24 hours of booking it.

Plus, the fact that you can check two bags for free when taking Southwest is a big bonus — especially with higher-priced baggage fees these days.

Cross-reference your cheap flights with Expedia.

In the US, I often cross-reference Southwest prices with Expedia ones. The latter, too, allows you to cancel your flight within 24 hours for no fee. You'll get a full refund, no questions asked.

If you use Expedia abroad, however, this is not always possible due to various airlines' restrictions. So be more cognizant before booking and call Expedia to see how much of the flight you'll be refunded should you cancel.

Use Skyscanner if you are flexible in your travel times and your destination

The travel fare aggregator site Skyscanner is a last-minute traveler's dream come true. Not only can you select "Whole Month" if you want to see the cheapest prices all at once from month-to-month, but if you aren't sure where to go, you can choose "Everywhere" and then go from there.

Like my experience taking three planes and a train to get to Switzerland, you may find, it's cheaper to combine modes of transportation to get to your destination rather than taking a single direct flight.

If you have a set budget, use Kayak

With Kayak's "explore" tool, you can type in your departure city and then how much you want to spend and what month or dates you'd like to travel. For example, you can put in Los Angeles, $150, and select the month of August (or particular dates) and see what options are available.

Always try budget airlines when you're traveling abroad

I spend most of my time country-hopping in Europe, so in addition to Skyscanner, I also check flight fares on the budget airlines Ryanair and Wizz Air — which often have flights for around $50 one-way. Ryanair sometimes even offers them for around $10.

However, read the fine print when you book with these airlines. Ryanair flights can be changed (but not cancelled) up to 2.5 hours before you fly, but are non-refundable. Wizz Air, on the other hand, will give you a partial refund based on when you cancel, or flight credit if you join their Discount Club.

You'll get other perks with the Wizz Air Discount Club membership, too, such as priority check-in and a flexible ticket, depending on which membership you get. If you're flying within Europe often within a calendar year, I'd recommend the membership.

Use flight alerts

With any airline or flight aggregator sites you use, signing up for flight alerts can help you, too, as they'll tell you when flights go up — or down — in cost.

Don't plan on booking last-minute when it's high tourism season

Some times of year are more conducive to last-minute travel than others.

Dubrovnik, Croatia, is my favorite city, and July and August are the busiest times of year for tourism. Flights and lodging are both more expensive that time of year, so if last-minute travel is my goal, I wouldn't attempt it that time of year.

Use Rome2rio to figure out your transportation at the last minute

Rome2rio is a great site that'll show you how much it will cost to get from X to Y — by plane, train, bus, ferry, or car (depending on what options are available). So, when you land at an airport, for example, you can use the site to see how you should get to your destination.

That means you don't need to waste tons of time and money planning your transportation, and can safely wait until the last minute to figure it out.

In many places you can rely on Uber or other rideshare apps

As part of my last-minute travels, when I arrive in a new city, I often take an Uber to my destination, as they're available in more than 700 cities in 63 countries and usually less expensive than taxis. Plus, they don't require any pre-planning like a shuttle bus might.

While public transportation is the economical way to go, buses and trains are not always running — and lugging your bag on and off potentially un-air-conditioned buses in the summer is not the most convenient option.

Some countries, such as Italy and Spain, also have ridesharing services for longer distances, such as BlaBlaCar. With the app or website, you can see who's heading to Granada, Spain from Barcelona, for instance, and get a ride that way, often much cheaper than other transportation options.

You can negotiate housing costs — especially if you show up at the property

A great perk in finding housing at the last-minute is the ability to negotiate.

For last-minute accommodation, I use Booking.com and Airbnb — often, you'll see the same places listed on both sites. The great thing about the former is that they'll offer last-minute price cuts and "deals of the day. All fees are included upfront, so there are no additional service or cleaning fees as there are with Airbnb.

If you're not desperate for housing, however, and have some spare time, I'd do a price check on Booking — but don't book — and then go to the property. Especially in the evening, many places are willing to give you a lesser price in person, since they'd rather make some money versus no money.

That's exactly what I did while traveling through Iceland in June, and many properties offered me 20% off without my even asking. One place even told me that's the best way for people to get deals — just show up.

In my experience, you sometimes can get a 50% discount when property owners see you're traveling solo. That discount wouldn't exist if you booked in advance, as online listing prices are usually fixed regardless of the number of travelers in your party.

If, however, you use Airbnb instead, I recommend messaging a few places versus just choosing one. Although it's great that Airbnb has an "Instant Book" feature — so a host does not have to approve your request and you can head right over to the property — it's best to try negotiating with a few places first.

To do so, find a few options you like around the same price range and then ask the more expensive ones to match the lowest-price one by creating a "special offer" for you — they can reduce the price of the room or remove the cleaning fee. This is not foolproof, but works more often than not.

Get free, last-minute housing with CouchSurfing

CouchSurfing.com is another great resource to find last-minute housing — and it's free. You just need to spend a few minutes creating a profile and then can look for a place.

Like Airbnb, people write reviews of homes they've stayed in, noting if the description was accurate and the host's level of hospitality. Plus, a "couch" can mean anything from a couch or futon to a spare room or yoga mat on the floor, so there's a wide range of options.

For food, use your phone — or the recommendations of locals

Although Google Maps' "Explore" option and the Foursquare app are great ways to find restaurants for a last-minute meal, I also ask locals for their recommendations, whether it's my Uber driver or a shopkeeper. That way, you can eat at a truly authentic place where the locals go, versus one made for tourists.