NEW YORK -- If you're on a budget but you'd like to fly somewhere for your next vacation, there's good news.
"Domestic fares are down 9 percent over a year ago and summer fares to Europe are down 19 percent," said Mike Fridgen, product manger for Farecast.com.
"Bargains are out there," agreed George Hobica, founder of AirfareWatchdog.com.
Examples: JFK to Paris, for under $500 roundtrip; Southwest's $49 one-way tickets, and once-in-a-lifetime dream fares from Newark to Hawaii, in the mid-$400s, including taxes and fees.
These and many other deals are easy to find online. But there are some strategies you can use to make sure you get the lowest possible airfares. Here are some tips from the experts.
RESEARCH: "The most important thing is to do your homework," said Michele Perry, spokeswoman for TripAdvisor.com, which just launched a new flight search aggregator.
To do your research right, you'll need to compare fares from many different sources. "Too many people get cozy with their favorite search engine, blithely thinking that it's the best," said Hobica. If there were one best Web site, he added, "the rest would be out of business by now."
"There's not one Web site out there that has the cheapest fare," agreed John E. DiScala, founder of JohnnyJet.com.
Sign up for newsletters and e-mail alerts from airlines that serve the routes you're shopping for, and from sites like AirfareWatchdog, JohnnyJet, Farecast and others, including FareCompare, Kayak, Orbitz and Travelocity. Many airlines post their best fares only on their own Web sites, including Southwest, Allegiant Air, SAS, Aloha, Aer Lingus, Qantas, Alaska, Air New Zealand, and JetBlue, Hobica said.
Absurdly cheap fares, like a recent $14 flight on JetBlue from New York to San Francisco, don't show up on booking sites because the sites can't earn a commission on them. But that fare was mentioned in an alert from AirfareWatchdog, in JetBlue's e-mail stream and on Twitter, Hobica said.
"They Twittered to death that $14 fare, but it was not on Kayak, Travelocity or Expedia," Hobica said.
Airlines may also make deals with some sites and not others, so you may find fares differ for the same flight on different Web sites.
Another source for news about cheap fares, DiScala said, is the message boards of Webflyer.com.
And don't overlook promotional codes. "If you sign up for an airline's frequent flyer program or the airline newsletter, some airlines will generate a promotional code that you can use to get a discount when you book," Hobica said. Often these codes are generated individually and can only be used once, so you won't find them on Web sites.
Finally, as crazy as it sounds, check out package deals. Sometimes it's cheaper to book a hotel and airfare package even if you don't need lodging.
DiScala said he recently saw an airfare on United for $590, but on Travelocity, the same airfare was $480 including four nights in a hotel. That's because hotels and tourism agencies sometimes subsidize airfares to bring people in.
NOW OR LATER: You'd need a crystal ball to know for sure whether fares will keep going down or if they're stabilizing.
TripAdvisor's Perry says "there's anticipation that we're fairly close to rock bottom,"
But Hobica says the news on the economy just keeps getting worse, and "the airlines are panicking again. Spring fares softened and they're softening more. I expect to see summer fares soften, too."
He added that "we're seeing a lot more low fares with no advance purchase, or just three days' advance, because the airlines realize that people are afraid to plan way ahead in this uncertain economy."
If you book now and the fare goes down later, some airlines, including JetBlue, Southwest and Alaska, give a voucher good for future travel for the difference, said Hobica. Others will refund the difference but charge a fee of $150 or more.
WATCH THE HYPE: Sometimes a fare is so low it seems too good to be true. And it just might be.
First, a lot of really cheap deals are one-way, and the return fare may be more, depending on when you want to come back.
Second, look for those pesky little asterisks next to the price. On international flights, taxes and surcharges could add up to several hundred dollars.
"You've got to be careful about the hype around the deals," Perry said. For example, she recently checked out one of Southwest's famous $49 fares, "but when I priced it, it wasn't the cheapest option with taxes and fees, plus it's only one-way."
TripAdvisor's new Flights finder has a "Fees Estimator" function that can also help you keep track of little things -- charges for food, checking baggage, even headphones. "If you're traveling with a family of four and everybody sends a bag, you could end up spending the price of a ticket on checking your luggage," said Perry.
DATES MATTER: Look for deals early in the week: "A lot of airlines release their sale fares on Tuesday," said Perry.
And be flexible about when you travel. "It's usually cheapest to fly midweek," she said.
You could also save big on summer fares if you fly early or late in the season, during the shoulder periods of May to mid-June or late August to September, in the weeks before and after peak summer travel, according to Fridgen of Farecast.com.
Newark to Honolulu, for example, is on sale in the mid-$400s through early June, but "once you get to June 15 on, it bumps up $200 a ticket," Fridgen said.
Similarly, JFK to Paris, Fridgen found a sample fare departing June 24, returning July 2, for $567. Push the departure date forward just one day to June 25, and the price goes up to $822.
Hobica recommends using a flexible date search. "Orbitz and CheapTickets.com search over any 30-day period, and include all international routes; Travelocity and CheapAir.com search over a 330-day period, but don't offer all international routes," he said.
COMPARE ROUTES: "Connecting is usually cheaper than a nonstop if you're willing to take a connecting flight," said Perry.
But weigh the risks: If you're switching planes, is there enough time to make your next flight? If there's a long layover, are you going to blow a day of your vacation in the airport, spending money on food?
And check out alternate airports. Perry's home airport is Logan in Boston, so she always looks at flights out of Providence, R.I., and Manchester, N.H., too. "Sometimes nearby airports will be cheaper," she said.
AirfareWatchdog has a search option to see the cheapest fares to any destination from a wide range of cities at a glance -- for example you can ask to see all the lowest fares to Paris from anywhere in the U.S.
In Europe, the cheapest destination airports include Dublin, Frankfurt, Shannon, and London Gatwick (not Heathrow), Hobica said. Even if you're not headed to those cities, you might save money by flying in and connecting to a cheap European airline like Ryanair or EasyJet to get where you're going.
For a quick directory of which budget airlines serve which markets, visit WhichBudget.com.
Just remember that it's not always easy to transfer between two airports near one city. It could take hours and cost a bundle to travel between London's Heathrow and Gatwick airports.