Determine your geographic search area. There are small airfields all over the world. If you are interested in small airfields as a hobby, choose several countries. Concentrate on those before moving onto others.
Order aviation visual flight photographs for the geographic search area. These are available from flight simulation websites, map retailers online and map stores. Flight simulation websites often post stories written by those who have taken trips to small airfields.
Locate small airfields by state. Free websites have search information. If you plan to fly to one of these, make sure it's still in operation.
Find small airfields around the world. Websites designed for planning trips by private plane have listings.
Learn the history of the small airfields you find. There are many small airfields with rich history in military and commercial development that are no longer in use but can still be seen, as well as others that are still in operation.
Trade information with others who find small airfields. Flight simulation websites and blogs have places where you can tell others about some of the great small airfields you find.