Countermeasures: Stick with a single mileage program and try to rack up enough miles to keep elite status, which often will give you free confirmed access to “preferred” seats — those on aisles and bulkheads. This works only on the airline whose program you’ve joined — not its partners. And keep an eye open for deals; airlines do sometimes offer “sales” on business-class tickets that are far less expensive than usual in terms of money and/or miles.

•  Mileage inflation: With car rentals, credit cards and hotel stays that can earn you miles, it’s perhaps no wonder that some programs might be charging more miles for your free flights. But look at the award charts, and that’s not necessarily true. (We say “necessarily” because you never know how many seats are actually available for those entry-level awards, or if they are ever available on the flight you want.)

Still, just last week, I booked a round-trip ticket to Moscow this spring for 40,000 miles via American’s site on partner Air Berlin. On Delta, flights to Europe start at 30,000 miles each way but can go as high as 65,000 miles each way, thanks to its three-tiered system based on availability. American also offers a two-tiered system of “MileSaver Awards” limited by availability and “Anytime Awards” that require more miles but eliminate black-out periods; anytime awards are not available on partner flights. The plus to this system is that you can actually use your miles to get flights on your preferred dates — but it may cost you more miles.

In addition, American has introduced Dynamic Awards, available only to program members who live in the United States, that are based on the actual fare of the flight you’re seeking at the time of booking — the same system used by Capital One’s “anytime” miles. Theoretically the Dynamic Awards should require fewer miles, but on the flight I checked —— Miami to Portland, Ore. — a MileSaver Award was available for 12,500 miles each way on the mid-March dates I chose, while a Dynamic Aware would have required 20,000 miles each way.

Countermeasures: Fly in the shoulder season, when mileage requirements are lower and seats are more readily available. If you have the option of waiting to within 14 days of travel, you may snag a seat anyway, as airlines do sometimes make additional seats available close to the date of travel on flights that aren’t heavily booked.

•  New ways to use miles: The best value for your miles, hands down, is a free air ticket that would cost you thousands of dollars if you had to buy it. But there are, literally, dozens of other ways to use your miles that include magazines, newspapers, dinners and charity contributions.

When it comes to using them for travel, miles from most airlines and those earned on American Express can be used for hotel rooms, vacation packages and car rentals. American, United and Delta programs all now offer “auction” sites. American’s offers “once in a lifetime” experiences, such as a weekend at the Country Music Awards in Las Vegas that includes air, hotel and seats for two people; at last check, the bid was 400,000-plus miles. Delta auctions include specialty experiences and resort stays. United’s offers hotels via an opaque site powered by Hotwire, where you can a specific number of miles for a hotel in a certain area but can’t see the hotel name until after you close the deal.

In addition, it is possible to sell your miles for cash. The airline programs prohibit it, but it is legal. You can check their value at dozens of online sites, including FirstClassFrequentFlier.com

As for my group cruise to Rome, we decided the number of miles and co-pays required were more than we wanted to part with. We decided instead to visit several national parks this fall and will buy air tickets for a few hundred dollars. But we’re planning early for next year’s group cruise, so we can snag that frequent flier ticket early.