Don't let holiday crowds at the airport bring out your inner Grinch.
Holiday travel this year is expected to reach "the highest level on record," with 103 million Americans on the move for year-end holidays, according to AAA. Most will drive, but air travel is expected to increase 2.5 percent, with more than 6 million Americans flying.
Holiday crowds can trigger long airport lines and jammed overhead bins, and make it tough to get on another flight if your original one is delayed or canceled.
"As much as you can, start thinking about Plan B," Ed Perkins, a contributing editor for SmarterTravel.com, told CNBC earlier this year. "If there is a problem, what are you going to do?"
Some of the best travel tactics require planning — picking a nonstop flight instead of one with a layover, for example, applying for trusted traveler status to gain access to priority security lines and avoiding airports prone to bad winter weather and other delays.
But even at the last minute, plenty of strategies can help travelers troubleshoot travel woes.
Most let you check in for your flight via an app and get a digital boarding pass, allowing you to skip the airport check-in line. Sign up for alerts relating to your flight — they're often the first you'll hear about a gate change or sudden delay, helping you react quickly, James Cury, editorial director of ThePointsGuy.com, told CNBC earlier this year.
Depending on the airline and airport, these may get you access to special check-in or security lines (which are often faster), or early boarding on the flight itself (for first dibs on overhead bin space), George Hobica, publisher of AirfareWatchdog.com, told CNBC earlier this year. Buy in advance, or even at the airport.
United, for example, charges as little as $15 per flight segment for such services. (The airline announced before Thanksgiving that passengers holding a "basic economy" ticket will soon be limited to one bag that fits under your seat.) JetBlue offers expedited security for as little as $10.
One line might be shorter than another, Perkins said. Depending on the airline and airport, you may have access to curbside bag check, or special lines or drop points for already-ticketed passengers who just need to hand over their bag.
The TSA advises arriving at least two hours early for domestic flights during the peak holiday season in anticipation of longer lines.
It also helps to know your options. See if you have multiple security checkpoints open to you, Hobica said. There can be multiple checkpoints per terminal, and many terminals are interconnected, he said, so you might be able to trade a longer walk for a shorter line.
Some airports, like Phoenix Sky Harbor International, also display average security wait times on monitors in the airport to keep travelers up to date.
If your carry-on bag won't fit beneath your seat, consider packing a smaller tote as well, Cury said. That way, if you're forced to check your bag at the gate, you can pull out any valuables.
"Figure out what would be your ideal situation, or least worst alternative, if your regular flight is disrupted," Perkins said.
With full flights, it's not a bad idea to have some sense of what your plans will allow, he said — could you take a flight that gets in early Christmas morning, or fly to a different airport in the area?
That lets you decide quickly if whatever alternative the airline is offering will work, or if you need to ask for a refund and make other holiday plans.