If the data is to be believed, an increasing number of us will be headed for destinations far and wide as spring turns to summer. Credit: Benjamin Beyers for The Motley Fool.

"I'm leavin' on a jet plane ... I don't know when I'll be back again."
-- Peter, Paul & Mary, from the John Denver song "Leaving on a Jet Plane" and recorded for the 1967  record Album 1700.

OK, so no one says they're "leaving on a jet plane" anymore. It's still a nice image, isn't it? The thought of climbing the stairs to a large airliner, headed for who-knows-where?

More of us are dreaming of doing exactly that. According to a January report from American Express, 57% of consumers have leisure travel plans this year (up from 55% in 2013), with 47% of respondents saying they'll spend more and 32% saying they'll fly more.

Airlines have taken notice. In December, Delta Air Lines (DAL -0.45%), American Air Group (AAL -1.60%), and United Continental (UAL -1.82%) boosted fares between $4 and $10 on most domestic routes. All three have seen some growth in the first half of 2014, though United has had a tougher time than its two main peers.

Overall, airfares are up 15% since 2009 and could climb another 5% this year, according to data compiled by tracking site FareCompare.com. Call it a harsh dose of reality for those longing to live the fantasy. Leaving on a jet plane isn't getting any cheaper.

Still determined to get away? I can't blame you. Here are five of the best tips I've found when it comes to shopping for airfare deals:

1. Go to the airlines first; then compare.
When searching for deals, your instinct may be to turn to a popular aggregator such as Kayak or Google's flight-specific search database. Yet you may miss some of the best bargains in doing so. Airlines tend to keep their cheapest fares close at hand for as long as possible, pitching directly to frequent fliers or those who visit their websites directly. In the case of Southwest, online booking is available only via the airline's website. Search the carriers first, and then use Kayak, Google, and others for better offers.

2. Embrace a flexible schedule.
Airlines rarely exhibit pricing power. But try to shoehorn a specific itinerary into the system and you'll invariably be left paying a higher overall fare. Know this going in, and be ready (and willing) to adjust your vacation plans to maximize your savings. Switching your intended flying schedule by 24 to 48 hours can cut your fare by hundreds.The catch? Airlines aren't keen to share this information, so you'll want to use Kayak or Google's "explore" feature when searching flights.

3. Take a lower-traffic route.
Heading to a high-traffic destination? Try flying through an out-of-the-way airport. Good examples include Gatwick rather than Heathrow when flying to London, Newark rather than JFK when flying to New York, Burbank rather than LAX when flying to Los Angeles, and Midway rather than O'Hare when flying to Chicago.

4. Use Twitter and alert systems.
Sites such as AirfareWatchdog.com and FareCompare.com keep close tabs on carrier sales and will often broadcast deals straight to Twitter. You can also find sales using social media to follow the airlines with which you've already registered as a frequent flier. JetBlue's "Cheeps" Twitter account is famous for broadcasting deals, having attracted more than 394,000 followers as of this writing.

5. Build your own itinerary.
Who says you need to book your trip all in one sitting? Consider booking a segment at a time to save cash. For example, say you want to travel from San Francisco to Washington, D.C., but a quick check of the fare sales shows big savings flying out of Seattle instead. Book the flight and then use the difference to book your trip from San Francisco to Seattle, pocketing the remainder.

Leaving on a jet plane may be getting costlier, but deals remain for those using the right tools.