A couple of easy ones come to mind.

Assuming that the SHTF scenario is an EMP type of event... Then a GREAT place to scavenge will be the highways, and rail-lines

Once the sheeple madness has died down a bit, The roads will be littered with vehicles with piles of stuff in them that people couldn't carry when they were forced to abandon their rides. Granted, others will pick some over, but most of them will be carrying their own stuff. Given accidents and general mayhem, it wouldn't even need to be an EMP, as people drive stupid to begin with, and in an emergency, there will be blocked roads all over.

These will also be a great source for fuels (diesel, gas, oil)

There will also be tractor trailers and trains stopped all over the place.

I have an old tractor that will run no matter what. I could fill the bucket with jerry cans, grab a siphon hose, and have access to tons of fuels. Throw in a set of bolt cutters, and now I could access the cargo on the trucks/trains.

Throw in a couple good chunks of chain, and if I happened across a fuel truck, or a grocery truck... I could drag the whole thing home.

Beyond that, there will be of course your neighbours. The ones that either didn't make it home, or bugged out to another location. I have one sheeple couple living near me, who pride themselves on "living one day at a time" they shop daily on their way home, and buy enough food for the night. Assuming of course that they didn't just have dinner out(again). I've sat in his kitchen, having a beer with him, and he opened a few cupboards looking for snacks, and every food cupboard was almost void of food. the fridge held nothing but condiments. The freezer had ice. I asked him what they'd do in case of a blizzard or something. "Jump in the truck and head to her mom's place in the city, or just stay in the city".

So what did they have? Lots of books, several musical instruments, tools, clothes... stuff! and in a SHTF scenario... 'stuff' can end up having multiple uses.