Video Game Level
Build a replica of a famous video game level. For example, millions of people have played the computer game "Counter-Strike," and a map called "Dust" provides the setting for many "Counter-Strike" tournaments. A replica of a famous game level such as "Dust" would be immediately recognizable to many airsoft players, who wiould delight in the opportunity to live out their video game fantasies in real life. A replica of the map "2Fort" from "Team Fortress" would also be certain to attract airsoft players from miles around.
Hedge Maze
If your airsoft field is based in a forest, add variety by turning a section into a massive hedge maze. Alternatively, construct a maze from wood to prevent players from seeing and shooting through the walls. A maze can provide opportunities for players to hide, and not knowing the way out lends an extra level of challenge to the experience. Create an ideal environment for Capture the Flag-type gameplay by building small wooden forts at opposite corners of the maze.
Urban Combat
Construct a simulated urban environment by placing walls inside a pre-fabricated steel building and painting them to look like brick or stone. If you hire professional contractors, you may even be able to add areas with stairs and ledges to your building, giving snipers places to perch. Not only would a simulated urban environment be a hit with airsoft players craving variety, but it would also provide a place to play during poor weather.
War Scenario
Airsoft is essentially a war game, but few airsoft fields make an effort to create a historically accurate environment. Pick a war--the Vietnam War, for example--and design your field so that it truly reflects the feel of that environment. Use plants native to that area of the world, and put up a few inexpensive wood structures that look as though they could have existed in that location and era. If it is appropriate for the war you have selected, dig a trench in the middle for combatants to fight over.
Movie Set
Recreate a set from a famous film, or simply use a film as inspiration to draw upon. For example, the Nakatomi office from the film "Die Hard" might provide fertile ground for ideas. You can use items such as cubicles, desks and old computers to construct a simulated office environment where players can act out terrorist and hostage scenarios.