Tip #1: Make your reservation early.
Many discount fares require that you make a reservation 7, 14 or 21 days in advance, depending on the fare.
Tip #2: Flying on a weekday usually costs less.
Flights departing on Tuesday, Wednesday and Thursday usually offer the lowest fares. Fares are sometimes (but not always) higher on Monday and Friday than on other weekdays.
Tip #3: Stay over a Saturday night
Most low fares require that you stay over at least one Saturday night before your return flight.
Tip #4: Consider an airport in the surrounding area.
You may enjoy significant savings if you are willing to fly into nearby airports. For example, when traveling to Los Angeles (LAX), you may want to consider flying into the Burbank (BUR), Orange County (SNA) or Ontario (ONT) airports.
Tip #5: Try an earlier or later travel date.
To get the lowest roundtrip fare, the same fare must be available on both the departing and return flights you select. If the fare is sold out on either of these, the price you end up with will be much higher. If possible, consider flying on another date.