First add a few layers of dirt as suggested above. Then hunt up the freebies by trekkiegrrrl/ernyoka and geralday. Trekkiegrrrl has a pile of junk on her site. (I hope she'd regard that as a compliment!) She's made broken bottles, cigarettes, flattened soft-drink cans, gummy spilled stuff, and dog shit, among other items. The morphing newspapers, used kleenex, and blankets are also wonderful for "atmosphere" of the scummiest. Geralday has flowerpots and spiderwebs, he might have a broken pot too. A flowerpot with something dead in it (there are trees and branches also in free stuff) will add a nice bit of irregularity to the corner. Carolly