When starting my research on travel hacking, I was most interested in getting free/discounted plane tickets.  I first learned that in order to accumulate miles, you need to be part of an airlines frequent flyer program.  Perhaps, the most valuable thing I learned was that it's not necessary to sign up for every single airline program out there, but rather to have an account with one airline in each airline alliance.  

What is an airline alliance?  
It's a group of airlines that have partnered together to benefit their customers through flights and connectivity.  

In terms of travel hacking, you can use your frequent flyer miles to book a flight on any airline within the same alliance in which you hold the miles.  For example, when Blake and I took a trip to South Africa, I used my United frequent flyer miles to book our flights.  For the majority of the flights (we had a lot of connections), we actually flew with South African Airlines and Ethiopian Airlines, all using our United miles.  Airline Alliances give you a lot of options when cashing in your miles for flights.  

There are three major airline alliances that you should know about.

Star Alliance: Adria Airways, Aegean Airlines, Air Canada, Air China, Air India, Air New Zealand, ANA, Asiana Airlines, Austrian Airlines, Avianca, Brussels Airlines, Copa Airlines, Croatia Airlines, Egypt Air, Ethiopian Airlines , Eva Air, Polish Airlines, Lufthansa, Scandinavian Airlines, Shenzhen Airlines, South African Airlines, Swiss Air, Singapore Airlines, TAP Portugal, Thai Airways, Turkish Airlines and UNITED AIRLINES.   

One World Alliance: Air Berlin, AMERICAN AIRLINES, British Airways, Cathay Pacific, Finnair, Iberia, Japan Airlines, Latam, Qatar Airways, Malaysia Airlines, Qantas, SriLankan Airlines,  Royal Jordanian, 7 Airlines

Sky Team Alliance: Aeroflot, Aerolineas Argentinas, AeroMexico, AirEuropa, Air France, Alitalia, China Airlines, China Eastern, China Southern, Czech Airlines, DELTA, Garuda Indonesia, Kenya Airways, KLM, Korean Air, MEA, Saudia, Tarom, Vietnam Airlines, Xiamen Air

You should sign up for one frequent flier program within each alliance.  I assume most of my readers are in the US so it probably makes the most sense for you to sign up for United Airlines, American Airlines and Delta.  Joining these programs is completely free!  You can use your miles in these programs to fly any other airline within their alliance.

You should never take a flight without being part of the airlines frequent flier program or another program in their alliance.  For example, If I'm going to pay cash for a flight to Thailand and I'm flying Thai Airways, then I will put in my United Frequent Flyer number at checkout, to make sure I get credit for the flight.  Thai Airways is in the same alliance as United, so I will gain United miles for taking that flight. 

What about budget airlines?  Sometimes, it makes the most sense to fly with a budget airline such as Southwest, Frontier or Ryan Air.  Typically, the flights are discounted and they have a more direct route to where you're flying.  Just be careful with hidden costs such as baggage fees, seat charges and exorbitant taxes.  These airlines aren't part of an alliance but if you fly them enough, it's beneficial to sign up for their rewards program.  I know a lot of people that prefer Mexico or the Caribbean for their vacations, so they take advantage of the Southwest credit card to earn rewards.  Do what makes sense for you.
 
This is the most basic and obvious way to accrue miles; actually flying with an airline.  But what if you don't travel all that much?  It's going to take forever to actually take enough flights to accrue the miles and then be able to trade them in for a free flight. 

This is the best part about travel hacking!  You don't actually have to get on a plane to earn thousands of miles a year!  See my next blog post for my top strategies on earning miles.