1. Check fare aggregators.
Websites like kayak.com, sidestep.com, and mobissimo.com search for the cheapest fares available on airline sites and other travel websites such as orbitz.com. A warning: Some low-fare airlines such as Southwest are not available; see Tip No. 5.
2. Have a flexible schedule.
Traveling with stop-overs and at off-times, such as the crack of dawn or the middle of the night, will yield great savings. You'll make up for the lost sleep after the new year.
3. Explore alternate airports.
They're usually served by low-fare airlines that couldn't get into the busier major airports. Also, their airport fees — which airlines add to the cost of your ticket — are lower. And most major airports are outside city limits, so you may end up closer to your grandkids' home in the suburbs, anyway.
4. Buy two one-way tickets.
Occasionally, one leg on a round trip ticket is cheaper than the other. Compare several itineraries online, then pick the cheaper outbound and inbound fares and buy them as separate one-way tickets.
5. Look for the new kids on the block.
New airlines will have cheaper fares and specials but they may not be available on reservations sites such as travelocity.com and orbitz.com; you'll have to go to the airlines' sites directly.
Find more tips on penny-pinching in our Monday Money Savers.