It's clear that these old rules are no longer sufficient. The marketplace has changed, and your search strategy needs to account for those changes.
Extras first, not last
You have to build the important extras into your search from the get-go, not wait until the final buying process. Be specific about exactly what you want to buy. Airlines are offering more packages and options, at varying prices, and you can't be a smart buyer unless you have a clear idea of what you want and what you don't want. Each airline prices and packages these various features in its own way.
Note any airlines on which you are trying to pile up miles, or if you have frequent-flier status or a credit card that covers some or all of these options.
Expect a connection
You will often find that your cheapest option is for a connecting itinerary rather than a non-stop.
If you check peak season trans-Atlantic fares, you may well find that the cheapest option is via Kiev, Moscow or Istanbul. Most cases aren't as extreme as these, but you have to decide whether you'd accept a connecting itinerary, with all the extra time, risks and hassles, to knock some big dollars off your cost.
The lowest fare isn't always the cheapest
The airline with the lowest base fare is not necessarily the cheapest after you figure in the extras you want. The most obvious case in point is Southwest: If you intend to check a bag or bags, round-trip, its no-charge policy for two bags gives it a minimum $50 cushion over any competitor that charges the usual $25 per bag each way. Similarly, you may find that some airlines' bundles result in a lower total cost than others' individually priced fares and extras.
Buy and cancel
If you find what looks like a good deal early in your search, you might want to go ahead and "buy," knowing that as long as you're looking more than a week in advance, you can cancel within 24 hours without penalty. Then keep on looking for a better deal.
This one doesn't show up on many lists, but it can be important. There are noticeable product quality differences in coach/economy among airlines.
Carriers like JetBlue, Virgin America and Alaska are niche players that compete on quality along with price. Flying on one of those lines may well be worth a few bucks more than flying on any of the "big three" giant network airlines or a low-fare airline. In Europe, Turkish has a somewhat similar reputation.
On the other hand, Spirit, Frontier and Allegiant are quality bottom-feeders. Most people would probably choose to fly them only if fares or schedules are much better than options available on other lines. Ryanair is the equivalent in Europe.
Avoid penalty fees
On many airlines — especially low-fare airlines — fees for checked bags, carry-on bags, seat assignments, printing a boarding pass, and other functions escalate as you progress from initial purchase to boarding the flight.
On Spirit, for example, if you want to check a bag, you pay $30 when you first book, $35 if you pay online after the initial booking, $40 during online check-in and $50 at the airport. You can print a boarding pass free at home, but pay $2 at an airport kiosk or $10 at an agent station. Other low-fare lines follow similar pricing systems.
Clearly, once you have identified what you want in the way of extras, pay for them as soon as feasible. There's no reason to wait until you have to pay what amounts to a "delay of game" penalty.
Airfare sales are back
After several years of inactivity, you can see some indications that limited-time airfare sales are back. Typically, you have only a short time — maybe even just a few days or a week — to buy promotionally priced tickets, but several months to fly.
The return of sales, however, poses something of a quandary: Do you buy up to three months in advance, as some old rules advocate, or sit around waiting for a sale? We have no ready answer there. The best advice: When you see a really good deal, pounce on it.
Excerpts from USA Today