What do you look for at your local thrift store? Fo me its fleece blankets for the car. (Many of which are just pieces of fleece material.) Great for insulation, padding cargo and covering valuables.

Wool Blankets, about 1 every 2 or 3 months

Picnic blankets; Fleece on one side, PVC/Vinyl on other

Nalgene Bottles for 99 cents

Storage bins for all the stuff I find at goodwill.

BIG duffles (100-120 liters) for everything.

Old type battery lanterns that use 6 volt batteries, fit an LED bulb and a modern battery for DOZENS of hours bright run time.
Oil lanterns, both wick type hurricane lamps and pressure lanterns.

Sometimes, good quality wool blankets.

BTW, the term "thrift store" is very little used here, "charity shop" is pretty much the same thing.

After looking for clothes for the kiddos, I usually head to the housewares section first to look at pots, pans, racks, blankets, candles, lanterns, Rupperware/Rubbermaid..... Sweaters, shirts, pants, jackets and snow clothes are always my hunt list as well. I'm also always on the look-out for bags, packs, trekking poles, and random anything. Second-hand stores are about my favourite shopping destination.

Many moons ago, there weren't very many thrift stores around, but there were "army surplus" stores in abundance - happy hunting grounds for impoverished college students looking for decent outdoor gear.

A lot was actually quite decent, although heavier than the top of the line civvie gear. When I became mil surp myself,and began to earn some money, I was happy to get lighter, brighter gear. But the militry stuff worked.

Keep your eyes open and you can find some fabulous bargains in thrift stores

I have found high quality wool blankets in excellent condition. I found three at the Seattle Goodwill stores: one no-name, one Faribo in practically new condition, and one vintage Kenwood in fine condition.

I've found high quality wool and fleece clothing, like a wool/fleece blend Mountain Hard Wear pullover, and several vintage LL Bean *heavy* wool sweaters, plus Scottish wool tartan kilted skirts. Most other stuff, I already own.

Spare high quality water bottles

You all must have a better class of thrift shops than we do in my town. We've donated much stuff over the years, but have never seen anything on the shelves even close to the quality of what we have donated. The shelves all contain pretty much junk, and overpriced junk at that. You can, however, occasionally find a used paperback book for cheap. If you don't mind missing sections in the middle. The intact ones cost as much as new on Amazon. I haven't looked at their clothing, maybe that's better.

...Just shop in ritzier neighborhoods

I have found both cheap tents and very expensive bivvy bags.

Spoons.

Not for eating with, but for playing.

May not sound like a prep item, but I’m a musician...you can never have too many playing spoons 😂

do any of you find stuff in alleys set out for the city trash and scrappers? I have come away with tents some almost unused along with at least one very good "like new" sleeping bag.
Coleman two burners are almost common.South Minneapolis has a lot
of retired folks and a canoes in the back yards tell me i'm
not the only camper around.

Wool Dress Pants, to use as Winter Clothing

Wool seems to be in fashion- finding wool pants and heavy wool shirts

I've scored a couple of wool-lined canvas duck chore coats at Salvation Army.

A new rolling duffel for a BOB.

Cast iron pans and scout "clamshell" cooksets for $2
-Blast

Spare pet stuff; water bowl for their BOB, leash, etc.

One great example are the larges duffle bags with the rolling wheels; a nice way to store and move gear. I keep my camping gear in one.