They will sweep your property with GPR (ground penetrating radar), commonly used to locate water and electrical lines but will show returns on buried fire arms as well. Hide stuff off the home site, preferably not at your BOL!
Solar ovens work great. If you're in a northern climate, alcohol stoves, propane and even a gasification stove would be better than a camp fire.
Beware of detection from above. Planes and satellite can spot human movement without detection.
People get the government they deserve.