Most people don't put antique stores high on their list when coming up with places to hunt down vintage clothing and accessories, but they can be among the best and most exciting places to find vintage treasures. Some of my favorite finds were found tucked away in tiny small town antique sales, often times marked low because the owners just weren't aware of the value. The same goes for flea market stalls run by people who may have but certainly don't specialize in vintage clothing--they often have the best deals to be found, and are less likely to be picked over.
Even if a store doesn't have any clothing items, it's likely to have antique jewelry and accessories that may surprise you. Vintage glasses, fascinators, lockets . . . A lot of times it's fun to spend time in an antique store just to browse and learn more about accessories of the past. Though it's a little hard to go out empty-handed.