You could spend ages trying to outsmart the airlines, but it would be a loser's game. There are, however, some simple guidelines to saving money on flights.

For one, in the world of air travel, time is money; the less money you spend, the more time you're likely to spend in the airport. If you're willing to make a stop or two rather than fly direct, or if you'll take on a layover more than 12 hours long, you'll save some dough. (Just keep in mind all that money you'll be tempted to spend at Chili's to Go, Starbucks, and Cinnabon, and the savings might evaporate.) Here are the other key things to keep in mind when searching for that deal.

1. There is no one magic bullet

"People would like a simple rule, but in practice there isn't a single day or time to buy," Patrick Surry, the chief data scientist for Hopper, an airfare prediction app, told The New York Times.

Moreover, there are plenty of myths online about how to get the cheapest tickets. It is not cheaper to buy tickets on Tuesday, for example, and there is no evidence to support that searching incognito results in better-priced fares, says travel expert Nomadic Matt.

Because airlines using complex pricing algorithms that are based on everything from time of the year, passenger demand, weather, holidays, time of day, competitor prices, and much more, it's impossible to predict future airline prices. Websites and apps — like Hopper — "are basically taking an educated (but probably wrong) guess," he says.

2. Be flexible when you fly

If you're flexible on when you fly, you could save a bundle. You'll find a better fare to Mexico during its rainy season rather than at peak holiday tropical getaway time, and save big if you don't demand to visit Rome in the high-tourist season (and heat) of August.

It's always cheaper to fly during the middle of the week than on a weekend, and early-morning or late-night flights will save you money.

Even "the difference of one day can mean hundreds of dollars in savings," notes Nomadic Matt, so be open to the penny-pinching possibilities.

3. Be flexible where you fly

When you're locked into where and when you want to fly, "No voodoo can change that," Nomadic Matt says. But there are those occasions when the world is your oyster, and you get to choose when you slurp it down. "When you become flexible, suddenly the entire world opens up to you and you'll find amazing cheap airfare!"

Google Flights makes it easy. Go to Google Flights and click the map. Put in your dates, home airport, and watch a world open up. There's always a deal somewhere!

4. Check each of these travel booking sites and put Google to work

Each airline search engine has its selling points — and its shortcomings. For example, budget airlines like AirAsia, Ryanair, and even Southwest often won't appear on large sites like Kayak, Expedia, or Orbitz because they don't want to pay a booking fee. Other times, the cheapest airline on offer has a site that isn't in English.

Kayak searches for "hacker fares," which allow you to fly out on one airline and return on another for savings. Skyscanner calls them mash-ups. Hit a few sites to make sure you're seeing everything that's out there. Nomadic Matt recommends Momondo, Google Flights, and Skyscanner.

5. Don't spend more than an hour searching

"If you're spending more than an hour booking a flight, you're spending too much time," says Nomadic Matt. Harsh words for the hand-wringing, purchase procrastinators among us. "Spend 30-40 minutes finding and booking a cheap flight at a price you're OK paying and move on with your life. I never second-guess myself on flights. You'll go crazy if you do."