Flying over the holidays could cost more this year. So far, the average domestic airfare for the weeks of Thanksgiving and Christmas is $383, about 4 percent higher than last year, according to Expedia.

As airlines fly fewer routes and planes to cut costs, there are fewer seats available. Flights are fuller than ever, and airlines can charge more. Where prices ultimately go for the holidays will depend on demand. But travelers can always save money by carefully using travel websites; being willing to vary itineraries; and taking advantage of airfare refund policies.

A simple but valuable strategy: If you find a good fare, jump on it.

Here are some ways to save:

Be flexible: Adding a couple of days to your trip before or after peak travel days can lower fares significantly. So can flying on Thanksgiving Day, Christmas Day or early on the morning of New Year's Day. These days tend to be less busy. Most travel websites have search options that make it easy to find the cheapest days to travel.

Look for connecting flights: Flying nonstop is ideal, but that convenience isn't free. Booking an itinerary that includes one stop could save $100 round-trip. Just make sure to leave plenty of time to connect so that even if your first flight is late, you don't miss the second.

Be careful booking an itinerary that includes a stop in a cold-weather city. Last year, a Christmas weekend snowstorm on the East Coast caused more than 10,000 flight cancellations, stranding passengers for days.

Fly, then drive: Some airlines have a virtual monopoly at certain airports, allowing them to charge more. One of America's most expensive airports is Cincinnati, which is dominated by Delta. To save money, consider using airports in Dayton, Ohio, Louisville, Ky., or Indianapolis.

Other airports are expensive to fly in and out of because they lack a low-cost carrier to keep prices in check or because business travelers are the primary customers.

Most online search sites can check fares at airports 50, 75 or even 100 miles from your destination. The savings are potentially big enough to make the car rental and extra travel time worth it.

Pick two different airlines: Most airlines now sell one-way flights at reasonable prices. One airline might be cheaper for the outbound flight and another for the return. You could even arrive at one airport and depart from another. Many sites automatically display these multi-carrier itineraries; others require separate searches.

Consider the 24-hour rule: Most big airlines allow passengers to cancel and rebook tickets purchased through their websites within 24 hours without penalty. After you book, check the next morning and see whether the price fell. Alaska, Continental, Delta, Southwest, United, US Airways and Virgin America all allow this.

Search multiple sites: The cheapest flight doesn't always show up on every website.

Expedia, Orbitz and Travelocity are the biggest online ticket-sellers. Sometimes better deals can be found on sites such as Kayak, Hipmunk, AirfareWatchdog, Yapta, FareCompare, CheapOair, Mobissimo and Fly.com. Southwest Airlines isn't included on some travel websites so check it directly.