Usually, plane tickets jump in price during the final three weeks before departure. Booking as soon as possible is one of the easiest ways to ensure you will get the lowest price. You should be able to secure the best rates if you book within three months to 30 days from departure.
Another reason to book early is to ensure you get the seat you want, especially for peak season flights. You may pay the same price for a seat that's next to the bathroom and one at the front of the cabin. If you wait too long book a desirable seat, you will need to pay the extra money to for a "premium" seat.
By looking for flights early, you are not required to buy a flight today because you prices will only go up if you wait until the last minute to buy. If you're not ready to buy a ticket today, you can set a price alert that will notify you when a ticket price increases or decreases. Ticket prices can fluctuate on a daily basis, even a small drop can result in a large savings if you need to buy a ticket for each member of your family.
Another way to save money is by having flexible travel plans. Two of the easiest ways to find cheap flights are to fly mid-week or on the actual holiday since fewer people travel on these days. You might also consider flying to a different airport. The alternate airport or travel dates might not be an option, but, flexibility is one of the easiest ways to lower your airfare costs.
If you aren't in a hurry to get to your final destination, booking a connecting flight can be cheaper than a non-stop flight. The search engines will let you filter flight itineraries by non-stop, 1 stop, and 2+ stops. Even flying mixed carriers might be able to save you some cash as well.
If you're going to wait until the final weeks to book, you might be able to find some last-minute deals directly from the carrier.
This option can be hit or miss as it depends on how badly the carrier wants to sell any remaining seats. Or, if they recently launched a new route and are trying to generate interest. The good part is that these specials don't always require you to fly a redeye flight just to save a few bucks!