When is the best time to buy holiday plane tickets?

While travel advice abounds for the best times to buy the most affordable holiday plane tickets, flying during some of the year's busiest travel periods generally isn't cheap.

In this era of packed airplanes, smaller seats and fees for extra leg room, what airline is going to offer inexpensive fares around Thanksgiving, Hanukkah, Christmas and New Year's? Common business sense dictates that high prices will follow high demand.

What are procrastinating travelers to do besides drive or take the train to get to their destinations? CNN checked with airfare experts for some general advice and ways to dull the price pain:

Be ready to adapt to changing trends

Trends in airline ticket prices are usually in flux. That great deal you got a couple of years ago might not be in play anymore.

Tracy Stewart of Airfarewatchdog warns that because of airline mergers and resulting cuts in capacity, fares on some routes may be might be higher than what you paid just a few years ago.

But that can work in reverse as well: "On the flip side, in markets where service has been recently boosted, you may even be pleasantly surprised to find fares lower than five years ago," Stewart says. "So don't be discouraged by years past."

Bottom line: When it comes to winter holiday ticket prices, nothing is set in stone.

Thanksgiving

When we're counting our blessings, Thanksgiving ticket prices aren't usually among them.

"Prices for Thanksgiving travel start high because the airlines know travelers have little flexibility in terms of destinations and dates," says Patrick Surry of Hopper Research.

He warns that "the busiest and most expensive day to depart is Wednesday." (That's November 22 this year). Same holds true for a Sunday return (November 26). He says you might save money flying on Thanksgiving morning and returning midweek.

Cheapair.com also encourages flying in and out on nontraditional days. It says the cheapest departure date overall is Monday, November 20, and the cheapest return dates overall are Friday, November 24, and Tuesday, November 28.

Christmas and New Year's

Generally, Christmas and New Year's function much like Thanksgiving: High demand, high prices. Again, off-peak flying is your friend.

"Christmas is on a Monday this year, as is New Year's Day, so the Friday and Saturday before each holiday are going to be the most convenient times for travelers to fly," says Amanda Festa of Cheapflights.com.

"Aim for middle of the week and early morning or late night flights -- in other words, flights that are less convenient -- to avoid crowds and get better prices," she says.

Are you cheap and flexible?

We don't mean to be rude. Being cheap and flexible is a good thing! If you don't need window or aisle seats and great flight times and connections, Airfarewatchdog's George Hobica offers some hope.

"The bargain bin only has middle seats far from your traveling companions and 5 a.m. or red-eye flights," Hobica wrote in an email.

"I recommend that people keep on looking several times a day every day of the week and pounce when a price seems reasonable," he said.

Always look into alternate airports -- remember, the New York area has five airports and Houston has two -- and check Southwest.com in addition to Kayak or other search engines, he says.

On some supercompetitive routes (think Chicago-New York), Hobica says, there will always be "a few scattered seats and flight times that will go on sale."

Don't forget to count the fees

Remember to factor in baggage fees, extra leg room fees and food purchases before booking flights. Airline credit card holders may get a free checked bag and other perks. And make sure you consider your ground transportation costs as well.

Next summer, think 'winter'

It can be difficult to think about cold weather and the holidays when you're going to baseball games, swatting mosquitoes and running the A/C. But numerous travel websites, including Cheapflights.com, advise bookingyour holiday flights during the summer if you want to lock in rates rather than take a chance.

And Stewart of Airfairewatchdog says that "if you want to choose your favorite seat or preferred flight times, you're probably better off booking early."

Other advice

Finally, some other tips and considerations:

-- Insurance: Cheapflights reminds passengers to keep unpredictable winter weather in mind and consider getting travel insurance.

-- Early birds: Delays are less likely early in the morning, Orbitz says. You may miss your sleep getting up extra early, but you may also miss the crowds and misery.

-- Delay a week: Orbitz also points out that fares -- along with hotel rooms -- often drop a lot the week after Thanksgiving, Christmas and New Year's.

-- Presents: If you're flying to see family, Orbitz suggest shipping your presents instead of bringing on the plane. Saves hassles and fees.

-- Go global: International airfares can be a good deal for Americans this time of year, Stewart says. So if your family is understanding about Christmas in the spring, maybe a holiday vacation is in order.