7 secrets of booking a cheap flight, from a family that has been traveling the world for over 3 years

2. Do your research

Start by checking all of the possible alternative routes. "If the flight has more than one leg, search the separate legs yourself," Erin writes. Breaking up a direct flight into two or more smaller flights has saved the Benders up to $400 on one trip.

You'll also want to make sure you look at all of your airport options. Many cities have multiple airports, and oftentimes flying into the secondary airport will be cheaper. Of course, you'll want to make sure the airport isn't too far out of the way, Erin notes: "Sometimes the small amount saved is lost in the extra transport required. Keep Google Maps open so you can calculate exactly how long the drive will take."

Finally, check the ticket price for one person before checking the price per family, the Benders recommend: "Many airlines price seats differently and will charge you the higher price if you are requiring more then one seat. If you choose just one seat, view the price, and then change your quantity, you will lock in the cheaper price for all seats."

3. Check the airline website for promotions

Even if you've found what you think is the best deal on a third-party booking site, you should still check out the airline's official website. "Once I've searched Skyscanner.com or momondo, I will head to the airline's official website to see if they are holding any specials or promotions," Erin writes.

Booking direct can also save in other areas, she explains: "Sometimes if you require extra baggage or other 'optional extras,' a third-party booking agent website may not account for that, and the official airline site will. So if you need more flexibility sometimes it pays to go direct."

4. Find the coupons

Look for discount vouchers, which can make the world of difference for frequent travelers. The Benders use CheapOAir to find voucher codes. "I often get over $50 off," Erin says. "It just takes a few seconds and could shave dozens or even hundreds of dollars off your flights."

Also, join airline email lists, which feature sales and bargain prices. "While slightly annoying, you can end up saving a lot of money," says Erin. You could even end up with a free flight, which happened to the Benders thanks to an Air Asia newsletter.

5. Skip the extras

Most airlines, particularly discount airlines, will try to make money by letting you choose a specific seat for an additional fee. "You really don't need to choose your seats," Erin writes. "Just go with a random seat, and use the extra cash to treat yourself to a bigger cocktail when you arrive at your hotel."

Also, avoid paying for extra airline food at all costs and pack your own snacks. "Obviously, most airports won't let you bring water through the security checkpoints, but you may be able to snap these up near the gate and usually this will be cheaper than purchasing at 30,000 feet," she explains.

6. Book it yourself

Forgo using a travel agent, Erin — who used to work as one — suggests. "They will not check all low-cost airlines, nor will they check multiple days or separate legs," she writes. Ultimately, "they need to make money, so rarely will an agent find you a cheaper flight than you will or me!"

7. Pack efficiently and lightly

"Think twice about everything you pack into your bags," writes Erin. "Most discount airlines will charge you for every piece of checked in luggage. So the further you fly, the more you are paying for that big bag on wheels you're carting around. On a recent solo flight, Josh only took a small carry-on bag and saved over $100 by avoiding extra baggage charges."

Plus, if you don't check any bags, you don't have to wait around for them after you deplane.

See more tips for booking a flight on the cheap at "Travel With Bender."