I usually have a list in the back of my mind when I go to a yard sale or thrift store of things I'm looking for. I guess it would be better to have it written down and keep it in my wallet or purse so if I get a chance to stop by somewhere I'll know what to look for. Always check the item's condition. A $3.00 backpacking stove is useless if it doesn't work. Any preparedness item is fair game and you never know what you'll find at a yardsale that might not be on your list, so keep an open mind, but here's a few things to watch for if you don't already have them:
Kids clothes/shoes/snow gear/coats/etc. in good condition. Even if they're 2 sizes too big, KIDS GROW! I have a box or 2 for each of my kids to "grow into" and every spring/fall we bring it out and shuffle clothes around.
Camping/Outdoor Gear--propane/gas stoves, tent, fishing poles, etc. I got a volcano stove and accessories at a yardsale once for $40, the one we bought new was $129 without any extras!--now it sits in my storage waiting to be used (guess maybe I should get it out and practice with it).
Firearms/Shooting stuff (this is my dream yardsale!). Unusual to find guns for sale, but every once in a while someone is wanting to sell one. We had a yard sale once and someone asked if we had any guns, (of course we weren't telling or selling) so I guess it doesn't hurt to ask even if you don't see any. I have seen a trap thrower, reloading press/dies/scale, boxes of shotgun shells, you just have to keep your eyes open.
Cast iron or other heavy pots/pans, dutch ovens--great for outdoor cooking.
Old candles--light is always good, but even if you can't use them for a candle, you can always melt them down for egg carton/lint firestarters or tuna can stoves. (we'll discuss these another time)
Canning and Food Preservation--canners, jars, canning tools, dehydrator, meat grinder, etc. I've seen all this and bought a lot of my own canning/food gear at yard sales.
Tools. Even crazy old timey tools--we just got a forge from a farm auction in Denver (My husband knows what to do with it--I think I'd just have to put a board over the top of it and make it into a table.)
NON ELECTRICAL entertainment. Board games, etc. If the power's out, you'll need something to do!
Fabric. This is because I love to sew, but it wouldn't hurt anyone to have a few yards of good heavy fabric around to repair pants, tents, whatever with, and fabric at yardsales is amazingly cheap! I sew reenactment clothes and made me a skirt once from a chunk of fabric I got for 35 cents! I love it! (Reenactment clothes already made cost WAY more than 35 cents!)
This is not a comprehensive list. Keep in mind any gear you might be looking for at the time you hit the sale. At one point we were looking for an old wood stove. Now we found one and we're looking for triple wall pipe to go with it so we can install it.
Not sure why I'm dreaming about yard sales in the dead of winter . . .
What's on your list?