If you know some deserted or have your own land you may wish to spend a day tidying it up and creating your own airsoft or other millitary simulation game arena. this is an instructable with a few tips on how to get the most out of you resources and how you can minpulate them to give your team the edge if you desire.
Step 1: resources
you need to look at what you have to play with, pieces of ply, palets or metal. also you must look at the area you have, is it woodland, industrial and can you adapt what it is to a skirmish arena with minimal effort.
you must also concider what weapons and the number of people you will be housing, because theres no point housing a sniper nest if you only have a springer pistol.