Here are some tips on finding cheap airline tickets, as well as a list of popular budget airlines.

1. Start checking prices 4-5 months in advanced
2. If traveling during peak season, purchase your tickets as soon as possible
3. The cheapest tickets are usually the ones for flights on Tuesday or Wednesday
4. Sign up for e-mail updates on ticket sales
5. Check and compare ticket prices from different entering points
6. Use websites like Momondo, Skyscanner, or Kayak to find cheap airline prices, but always purchase through the actual airline’s website
7. Most budget airlines only have airport hubs in major cities, so be sure to check out multiple budget airlines and where they fly into
8. As with everything, check the online reviews and be ready to compromise comfort for cheaper prices

Disclaimer: I have not traveled on many of the airlines stated below, they are just well-known budget airlines. I have used a couple, but I prefer on ground travel if it is possible.