In a post-atomic world, nothing is better than going around the wasteland to pick up waste, junk and all that glitters. There are two ways for scavenging: in cities and in encounters around the map. Scavenging in cities while safe is very slow process. The much better options is to scavenge though city ruins encounters.
To do so enter empty urban encounters(in the same time checking whether you didn't hit on NPC encounter - if thats the case run to the exit grind as quick as possible) and search for possible objects.
While scavenging try to avoid routes between cities. Other players might hit your encounter and kill you, looting what have you collected so far.
How to scavenge
Just move the mouse over waste, junk piles, cars, trucks, paper machines, metal barrels, when an open hand appears click it and you'll have your resources.