There are a few basic rules you should adhere to if you want to get the best deal on your airline ticket purchase. Generally, the most important rule to follow is to purchase your airline ticket as far in advance as possible. Last minute bookings will generally yield the highest ticket price. If you see a good deal on a ticket, purchase it right away. In this day and age, everyone is looking for the best airline deal, and the good deals sell out rather quickly. Another good tip is to choose round trip tickets vs one-way tickets. Generally you can find better deals on round trip tickets.
Travel on weekdays or off-peak hours. The less popular the day and time, the better chance you have at scoring a cheap airline ticket. Also, some airlines give special discounts to certain groups, such as senior citizens, veterans, or students. Check with airline to see these special prices.
Last, but not least, always check the airline website or call them directly before purchasing to see if there are any deals going on. Generally, airline websites will have a deals or discounts section that you can browse. Good luck!