I have a whole chapter dedicating to scavenging on the remains of a collapsed society in my book “The S.H.T.F. Art of War.”
Here’s something to keep in mind while you are out on one of your scavenging excursions. The United States government currently uses very sophisticated unmanned drones to survey landscapes and keep an infrared eye on borders, war zones, enemies of the state and disaster areas. Knowledge is power. In a grid down, societal collapsed world, you can be sure that whatever is left of a government will still want to know what’s going on out in the apocalyptic landscape.