Traveling this summer? Don't forget about the 10-second rule to find best deals

PHILADELPHIA (WPVI) -- If you're planning to fly for vacation this summer, we have a warning.

Rising fuel costs and other factors are causing airfare to go up. The good news is thinking outside the box could save you some money.

Scott's Cheap Flights shared what they are calling the 10-second rule, it's a step you can take while searching for flights that takes just 10 seconds but could translate into pretty significant savings.

Usually, when looking for a flight, you search for a round trip.

But Scott Keyes of Scott's Cheap Flights said when it comes to domestic flights, switch that thinking and take an extra 10 seconds to search for one-way flights, too.

"Oftentimes when you search as a one-way outbound and a one-way return flight you'll actually end up getting a cheaper overall round trip flight," he said.

For example, say you're looking to fly from Philadelphia to San Francisco at the end of July. The cheapest nonstop round trip will cost you $859 on United. If you search the flights separately you can save $116 taking the outbound one-way on United and the return on American Airlines for a total of $743.

"It's not going to work every single time but it's always worth checking," he said.

Certain flight search engines, including Kayak, will sometimes do this for you but not always, so best to take the 10 seconds to check yourself.

And again, this is just for domestic flights. The 10-second rule doesn't work for international routes.

And no matter where you're going, if you're planning to fly during the summer, book now because those fares are only going to go up.

Also keep this in mind: "Trying to travel during early June, you're much more likely to see cheaper fares than if you were to go in late June," he said.

Keyes said the best time to book summer travel is actually in the winter months. And at this point, you might even want to consider a staycation for the summer and save that flight for September.

"Think about traveling in the fall or beyond, you know, after Labor Day. We are still seeing a glut of cheap flights popping up that are still very, very prevalent," he said.

If you're flying to Europe, Keyes said to try searching flights to cities near your ultimate destination.

For instance, flights from Philadelphia to Paris were at least $1,000 last week (April 25th) while flights to Dublin were less than $400. So it would cost less to stop in Dublin and take an inexpensive flight from there to Paris. Plus, you might be able to see two places for less than the cost of one.