Airports are designed to #1 get you to your flight, #2 get money out of you. Let's take a look at some ways to save money.
Book your parking as well as your ticket ahead of time. In this industry, we do not always know when we are going to need a plane ticket. We could get that call on Friday to be 2000 miles away by Monday morning. When ever possible though, book a parking space. Airport offsite parking is by default, cheaper then on site parking. Also, you can get up to 50% off by making a reservation.
Food is another big one. Can you say "captive audiance?" Its true. Even if you are picking someone up and cannot get through security. They know that the nearest fast food joint is usually 20 - 30 minutes away. Once you go through security, well, make it a few hours away. Try eating before you leave. At the very least, before you get to the airport. By not arriving hungry, you will be less tempted to grab a snack.
Reading material. It's nice to browse the magazine rack before your flight, but leave the magazines on the rack. Stop by your local grocery store and grab your reading material there.
Remember, the less your expenses are, the more your profits are.