Visit the website of the airport you will be changing planes at and print out a map of the terminal. When faced with a short time to get from one concourse to the next you will find a map to be very helpful.
In addition to your investigation of the airport layout, you should also identify shops and restaurants that interest you in the event that your layover time becomes lengthy.
Pro tip: add the Gate Guru app to your smart phone.
[Photo: Flickr | James Cridland]