Investigate the routes to where you want to go and then establish an alliance with the airlines that have the best flights to those destinations.  Align yourself with their loyalty program and start earning points every time you fly.  When you build status with an airline you may receive upgrades for yourself and one or more companions, depending on the program and status level.  These upgrades can be for seats with more room, closer to the front of the plane, and/or in first class. 

Another perk is that you will be allowed as many as three checked bags for free.  Some status levels will offer airport lounge access as well, especially if sitting in a premium seat.  This is a huge benefit when you have a long layover and need to crash.  There are also credit cards that enable free lounge access, which ours did. In addition, you will earn points for free flights and the higher the status, the better the chance of getting the flights of your choice.  So, all in all, the more you fly, the more you receive.

At the time of our travels, the One World Alliance (American Airlines and partners) had tons of flights to and within South and Central America, while the Sky Team Alliance (Delta and partners) had more affordable routes to Europe. The Star Alliance (United and partners), on the other hand, had great prices and routes to Asia and Southeast Asia and had the biggest worldwide alliance program overall.  This is an example of popular routes with the three major domestic airlines and their alliances, but we also found some of our best flight deals on promotional offers with international airlines, such as Turkish Airlines, Emirates, Thai Airways, SriLankan Airlines and Singapore Airlines.