I'm trying to think of what deer jerky and bait could be equivalent to here, not knowing what deer jerky signifies over there 🤣 Some suggestions I might include, however:
Collecting roadkill. If it was in good condition (or, presumably, he'd run something down himself) my old af neighbour used to take it home to make it into stews. My cousin turns her roadkill treasures into taxidermy trinkets, and keeps the bodies in the freezer until she's ready to...tax their dermy, I guess.
Collecting bones used to be a fun activity for us. Found a really cool badger skull by the river once. Cousin's house was down the hill from a graveyard and curiously there were some bones in her garden which looked a bit human (mostly finger and toe-like), so we'd collect those too. Aunt told us she'd found a human skull in the garden once, but she might've been joking. My dad gave us a bunch of bird bones he found cleaning the chimney once about 20 years ago, which are pretty fragile but I've still got them
But! We grew up in the countryside and Snape came from a sort of city, so I'm not sure how well that translates; would there be an abundance of animals dying by the river in Spinner's End? Maybe. If he had a chimney and if they cleaned it, I'm sure there'd be the odd set of bird bones for him to collect, and frogs and stuff maybe, and bugs. As a kid he'd be catching those, no doubt. He certainly keeps his jars of slimy things on display in his office in the books for no other reason than he likes having them there, because the slimy floating things are still in his office even when he's not teaching potions any more in HBP
Also, I think my nan used to bait and catch pigeons on her windowsill during the war, to make into a pie or whatever. I can see Snape attempting that.
Veering away from 'trashy' to just straight up frugal for a minute longer, I think he'd be the sort to have things in his fridge/cupboards that are way worse than live bait. In his house, every piece of food is kept in various stages of decomposition because wasting food is a cardinal sin when you're poor, and that's not really something you grow out of even with a steady income - but he's not really at Spinner's End enough, or eating often enough, to use it all up. If he were alive today (and, ofc, he is) he'd still have food from before sell by/use by/best before dates were a thing, and he's not getting rid of it. If the tin hasn't blown, it's good to eat. If the milk is only a bit iffy, it's fine to drink (and his idea of iffy is uh. intense. perhaps even lumpy). If he's got bread that's gone mouldy, he just picks the mould off or toasts it. Same for cheese; just scrapes it off. The chicken smells weird, weird enough that most people wouldn't touch it, but he's just like, whatever, and cooks it up anyway. There's also plenty of jars in that fridge full of substances of unknown provenance, which arguably at some point were edible, but it's hard to tell now what they even are. But he has a stomach of absolute iron so even when he eats something that very much did not pass the sniff test, he still feels fine. The cheese is also right next to his collection of dead animals he found by the river last week. He'll add it to his collection of jars at Hogwarts when the term starts again. I also like to think he also has a real problem throwing anything away, ever. "Who knows when you'll need the scrap fabric from that old coat that can't be repaired, or twenty old newspapers? That bit of wood I found in a skip could be useful for something. Best to hold on to it."
Back to 'maybe trashy' (with all the appropriate caveats about discrimination along the lines of class and socioeconomic status etc etc. Assume I said them here). Arguably smoking is considered pretty trashy now, but maybe it wouldn't have been back when Snape grew up. My aunt started smoking at 14 because everyone did, apparently. Ultimate trashy smoking behaviour is, ofc, rollies. A pipe seems a bit too distinguished. Buying a pack of straights is for the weak (and they're more expensive).
Tattoos, maybe? Obviously anyone with a tattoo knows that certain generations here can tend to have certain ideas about tattoos, although they're generally more acceptable on men. Ideally for trashy!Snape he's either gone somewhere dodgy and cheap and the ink's blown and it looks... interesting, but maybe he did them himself? That would be fun
Owns exactly one saucepan; never cleans it. Calls it "seasoned" if anyone were to dare to ask
Eats toast over the sink, rather than using a plate. Saves on the cleaning
At home, uses old Quality Street tins, marmalade jars, and Chinese takeaway tubs for potions ingredients
Has one mug for tea. The inside is black and fuzzy, and he likes it that way. Would sulk for a week if anyone cleaned it (by which point it would be black and fuzzy again. he likes a Lot of strong tea)
