Just who are these travelers unearthing cheap fares to Europe for $200?

Planning a multi-city Europe trip can be expensive. Thus, you need to  learn how to find the cheapest flights to Europe.

On a regular day, flights from New York to Barcelona or from Los Angeles to Paris round-trip can show for well over $500, but it's very possible to find flights to Europe for around $200.

1. Fly off-season and during the week

Choose an off-peak time of year to visit: There is less tourist activity from September through March when you won't be competing with a lot of leisure travelers for seats.

Note that the cheapest fares will be on Tuesdays and Wednesdays; avoid Friday or Saturday flights. Midweek isn't popular with leisure travelers.

2. Sift through search engines

Online travel agencies (known as OTAs) and metasearch engines are two types of third-party online booking channels.

With a metasearch site, you'll find fare and then be passed directly to the airline's website. Metasearch sites will also include mix-and-match flight options that might consist of flying the outbound leg to Europe with one airline and returning home with a different carrier. Metasearch sites will find the lowest fares because they are comparing data from a number of sites and sources, including the airlines themselves.

3. Book your flight as far in advance as possible

Booking 3-6 weeks ahead of time is usually the best policy. Most airlines dramatically increase their prices once they sell enough seats on a flight to cover their costs.

4. When to search

The best time to search for flights is usually just after midnight when companies reduce the prices on the flights that weren't booked during the day. Studies show that people who book at midnight on Tuesday tend to save about 6% on their trips.

5. Buy during the prime booking window

The "prime booking window" is from 4 months to 3 weeks before departure. Buying more than 4 months ahead of time will likely mean you'll pay a premium for your preferred date.

6. Be willing to fly from a different departure city

If you live in a city that's not a major hub (nor an international airport) like San Francisco, New York, Chicago, or Houston, then flights to destinations in Europe are always going to be more expensive.

Bring the cost down significantly by flying to one of these larger hubs within the U.S., first, and then catching a flight to Europe.

7. Choose a less popular destination airport

Airlines can save big (and pass those savings on to you) by flying into less popular airports, meaning it may be worthwhile to fly just a little out of the way if you have your heart set on a destination like Paris or Rome.

The trick is to then fly into one of the cheaper hubs, then grab another flight or means of transportation to the city you want to go to.

If you have your heart set on visiting Europe this summer, go for it. It just takes a little bit of patience, flexibility, and resourcefulness.