4. Be part of a plan
Having a frequent-flier membership can earn you more than just free flights on your airline of choice. If you fly often enough with a particular airline, you can earn elite status, which often starts at 25,000 miles and can bring you a wide range of perks. Frequent-flier credit cards are another way to add miles, too.
Travelers with "status" are more likely to receive a free upgrade than the average frequent-flier member, says Sullivan.
By being loyal to a particular airline, your odds of being upgraded by that carrier gain altitude, says Sullivan. She encourages travelers who want to earn elite status to stick with the main carrier or carriers at the airport they most often use.
"The reward will work both ways. The people who fly the most are rewarded the most," she says.
5. Pay for part
If you're willing to cough up a bit of cash, or use your frequent-flier miles, you also may be able to get upgrades at cut-rate prices.
If seats in business or first class are vacant, they may be offered to economy-class travelers at check-in. Frey recently paid $90 for an upgrade on a flight from El Paso, Texas, to Miami. "You have to be on the lookout when you check in," he says.
Another option is using frequent-flier miles. While you may encounter turbulence booking a flight using miles, it's often easier to book an upgrade, Frey says. The miles are "almost like currency."
Whatever your strategy for trying to earn an upgrade, Frey says the most important thing to keep in mind is that "there's just not as many seats to go around these days."
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