When some people hear the word "thrift store", they get scared. They think to themselves, "Oh my gosh, I can't wear clothes other people have worn!" Honestly, for a long time I felt the same way too. It grossed me out that the adorable dress may have been worn by someone else. But you know what? I finally got over it.
As an avid thrift store shopper, I have compiled quite the system. First of all, let's just get something straight. There is a huge difference between a thrift store and a consignment store. A consignment store usually has a better quality of items, because the store owner can pick and choose what comprises the inventory. But that's not to say that all thrift stores are bad. Just give it an eyeball before coming to shop there.
When buying from a thrift store, there are several steps you need to follow. Let's say you found the perfect designer jacket. What you want to do next is smell the garment. You may look nuts but it's important. If it smells like mold, cigarette smoke, or cat pee, put it back. (And, yes. I did just say "pee" on a fashion blog. I'm real, folks.) Those are odors that linger, and no piece is worth smelling funky.
Once it passes the smell test, give it a once-over. If you spot any rips, judge their "fixability". (Generally, chiffon-y or sheer shirts can't be fixed without showing, but there are exceptions.) Stains are an ultimate no-no, unless the shirt is particularly patterned, the stain is very small, or in an inconspicuous place.
Finally, judge the quality. Tug on the seams a bit, checking to see if it rips or stretches out of shape. Check out the lining, too, while you're at it.
If your piece passes every test, you are good to go. Snatch that piece up and wear with pride. (Just wash it first, of course.)
Typically, I won't buy undergarments or hats at thrift stores. Even if it does have the original tags on it, there's still a pretty good chance that someone has worn it. Better safe than have head lice.