First and foremost, make a decision regarding your date of travel. For the most part, airlines charge lower fares when flights commence on a weekday. If you are traveling from Boston to Miami, for example, and you want to stay for six days, you will most likely receive a better deal if you fly on Thursday and return the following Wednesday, rather than starting or ending your trip on Saturday or Sunday. Also try to be flexible with your departure time; if you don’t mind an early bird departure, or arriving at your destination at night, you will have a greater chance of getting the lowest air fare. And if you are not in a hurry, an itinerary that includes at least one stop should be considered, for this too will expand the number of flights from which to choose, thus increasing the possibility of finding a better price.

Your local travel agent and the online flight search providers work pretty much the same way, in that they scour the marketplace to match your needs with what is available. Today, most of the best deals on domestic flights will be found when booking a trip less than 3-4 weeks in advance. This is because airlines today offer special discounts that are similar to most other retail sales — they are ‘for a limited time only’. A quick comparison of several of the major online travel sites will reveal this. The trip taken next week will cost $400, but the very same flights will cost $500 if booked for next month.

International travel is a bit different, because of the greater likelihood of traveling via more than one airline. Your best bet here is to compare the fares offered by several tour agencies that specialize in a particular country or region. These agents broker deals to ‘purchase’ blocks of seats at what is often a staggering discount. However, unlike domestic travel, these trips should be booked as far in advance as possible, at least 90 days in most cases, because these fantastic prices are gobbled up quickly by those who have experience in foreign travel. And although these are the lowest air fares available, they usually are non-refundable, and carry a heavy penalty for changing departure dates.

The most important thing to remember when trying to find the lowest air fare, whether for domestic or international travel, is to plan your trip in advance, and be ready to make a couple of sacrifices. Your entire trip, whether for vacation or business, is affected by the dates and time you fly, so flexibility is key.

Competition, like in any industry, affects airline flights. In order to stay competitive, many airlines will run a discounted ticket to undercut the discounted ticket run by another airline. Some routes seem as though they never go on sale, commonly due to the fact that an airline holds the market share for that route, making it unnecessary for them to undercut other airlines.

The law of supply and demand is at the heart of many airline prices, making it less expensive to travel on weekdays, and at off-peak times of the year an hours. While it seems insurmountable to search every possible option for days and times for a flight, ask for the lowest fare, rather than specific dates when possible. It is advisable to try searching for smaller airports (Midway rather than O’Hare, etc), flights during the winter (if you must fly around the holidays, flights are usually less expensive on the holiday itself than the day before or day after), redeye flights, flights that include a Saturday stay, weekday flights (particularly Tuesday and Wednesday), discount airlines, and discounts for students, seniors, and clergy, dependent upon your qualification.

It is advisable to start your search at least one month in advance and if you do not find what you are looking for, keep checking. The same rapid price changes that took your amazing deal out from under you before can also help you find a new, cheap deal on a flight that was previously too expensive. While they can work to your advantage if you get one of the few seats at the low advertised rate, do not be fooled or disappointed by the low rates that are advertised. These low rates are used to “tease” customers into looking into flights with that airline or travel agency. While they must make some seats available at this rate, the airline allots a few surplus seats for advertising purposes, the airline equivalent of having seat-fillers at a Cher concert that you paid $200 for. It is a complicated and time-consuming process to unravel the politics and price structure of finding air fare specials. In many cases, it is easier to use a travel agent, who is highly trained and can devote their undivided attention to searching for the lowest fare; however, it is advisable that you do some homework of your own and are prepared with a knowledge of what fares and specials are available to a given destination.

Memberships to use airline lounges are always prepaid memberships. These memberships come in several kinds, but allow the passengers access to the lounge. The lounge has facilities for the business traveler including faxing, internet and telephone services. The lounge usually provides free drinks and food for its visitors. Some plans also include passes to bring a companion to the lounge, special seating arrangements on flights, and special check-in policies. If you need to alter your ticket, they can usually handle that in the lounge. These memberships run from $250 to $800 per year. If you travel a lot, or experience delays in your travel on a regular basis, these memberships are well worth it. Even better, if you can talk an employer into paying for it. Some programs offer memberships by day, so if you get stuck somewhere, it is worth inquiring into these programs. The lounge is much better than sleeping on the airport floor. A membership is usually good for one year.

Another type of loyalty program is the ones that trade milage for free or discounted airline tickets. There are a few airlines that charge a small fee for these programs, but all United States sirlines have a program that is free to join. Most of these programs need to be joined before you fly and take one or two months to complete your application. A few require a flight before you can join. The best program to join is the ones that you will actually use. Remember you can join more than one plan.

My local airport (Oakland) flies mostly Southwest. This would be a good program for me to join, because it is local, a large amount of flights avaiable and I do tend to fly economically as possible. The other thing to look at is where you might fly. I happen to use Alaskan Airlines often to fly to Portland or Seattle. I can take other airlines, but Alaskan seems to offer the best deals. So, it would make sense for me to also join a milage plan for Alaskan airlines.

You might want to join a few of the larger milage loyalty plans (since its free) in case you fly to other areas not served by your other memberships, or want to do some international travel, areas often served by some of the larger airlines. Two examples of a large airline plan would be United’s (the largest airline in the world), Delta or American Airlines. Another milage reward plan to join is Star Alliance which includes 27 airline companies including United. Air Canada and Air China. Most of these airlines are international, but if you fly overseas you will probably be using at least one of these airlines.

Airline membership plans are a nice benefit to have. I don’t know of anyone who has wished they never had the points. You will have to do some research to find your best options. The easiest way is to sign up for any plan you think you might use at some point in the next year or so. Then you are ready to make the best choices of which airline to use.