With increased vacation travel competition between airlines, if you are planning a summer flight, you can save serious dollars by shopping around and in advance.

Your best bet is to contact a travel agency or visit one of many Internet sites for information on all airlines flying to your destination. If you are not Internet savvy, a travel agent can find virtually all airlines and fares as well as special promotional deals. Watch newspaper and TV ads in which airlines advertise discount plans and ask a travel agency about them. Some airlines offer back to basics plans with flights at bargain prices but few extras. If you are willing to forego some creature comforts (such as extra peanuts or a warm face towel), you can save money.

Here are additional things to consider:

Be flexible in your travel plans in order to get the lowest fare. The best deals may be limited to certain days of the week or hours of the day. After you get a quote, ask the agent if you could save even more by leaving a day earlier or later or by taking a different flight on the same day.

Plan as far ahead as possible. Some airlines set aside only a few seats on each flight at the lower rates. The bargains often sell out quickly. But sometimes air carriers make additional discount seats available later. If you decided against a trip because the discount fare you wanted was not available on the desired date, try again, especially just before the advance purchase deadline.

Some airlines may offer discounts that others don’t. Fares could depend on which airport you use. Check Bangor, Portland, Manchester, N.H., or Boston point-of-departure airlines and rates. A connection (change of planes) or one-stop flight is sometimes cheaper than nonstop.

Does the airfare include services airlines traditionally provide such as meals and free baggage handling? If you have a connection involving two airlines, will your bags be transferred? Can you get an advanced seat assignment? If you are stranded, will the ticket be good on another carrier at no extra charge? Will the first airline pay for meals or hotel rooms during the wait?

Many discount fares are nonrefundable so if you pay and later cancel your trip you will not get your money back. Some fares include penalties for changing flights or dates even if you don’t want a refund. You may also have to pay the difference in airfares if your bargain fare is not available on the new flight.

Some airlines will not increase the fare after the ticket is issued and paid for. Simply holding a reservation without a ticket does not guarantee the fare. Other airlines may reserve the right to collect more money from you if the fare you purchased increases before departure time. Before you buy your ticket, determine the airline’s policy on assessing increases after the ticket is purchased.

After you buy your ticket, call the airline or travel agency once or twice before departure to check the fare. Fares change all the time, and if that same fare goes down before you fly, some airlines will refund the difference. But you have to ask.

Differences in airfares can be substantial. Planning in advance and comparison shopping between airlines does take time, but it can lead to considerable savings which you can spend on that extra set of Mickey Mouse ears or a T-shirt that says, “Gramma went to Seattle and all she brought me was this lousy shirt.” But shopping for souvenirs is another story. Happy landings.

Consumer Forum is a collaborative effort of the Bangor Daily News and Northeast COMBAT. Send questions to Consumer Forum, Bangor Daily News, P.O. Box 1329, Bangor, Maine 04402-1329. COMBAT is a nonprofit organization with annual dues of $10. For membership information, write to the above address.