Shopping in a thrift store can be a little (or a lot) overwhelming at times. In order to make a thrift trip successful, it's wise to have a strategy in mind. Otherwise, it's easy to spend either way too much money or way too much time in the store. These are the tips I've used successfully over the past 15 years of shopping for clothes in thrift stores.
Set a budget
This may seem obvious, but having a maximum amount you want to spend helps you be discerning when you are trying to choose between similar items. Sure they're each only $2.99, but do you really need two pink shirts? Knowing you only want to spend $10 total will help you look critically at them both to figure out which is really the better bargain.
Have an idea in mind...
It's wise to go into the store with a general idea of what you might like to find. For instance, I've recently been looking for items in brown, since I realized I don't have much of it in my wardrobe and would like a little more. This thought helps to focus my attention when I first walk into the store and gives me a place to start when looking through the racks.
...but don't have an idee fixe
Looking for a specific item in a thrift store is almost always a recipe for disappointment. If you have your heart set on finding just exactly that pair of grey pants you wanted in Nordstrom but could not afford, you won't be able to see and appreciate similar (but not the same) the grey slacks hanging on the rack.
Know your style
When there are hundreds of shirts hanging on the rack, you could spend all day looking through them. It helps to have some basic rules to follow. For instance, I don't like tops that are too long, since they emphasize rather than minimize my hips. So I look for shirts and sweaters that fall just at the top of my hips. Know what you like and learn to recognize those styles quickly so you can work through the racks efficiently.
Know your colors
No, I'm not talking about having your colors "done," though that's an option (and you can probably find a book to guide you in a thrift store!). But have an idea of what colors work for you and which ones just don't. I stay away from most reds, fuschias and certain acid greens, and this saves me time, especially when the racks are organized by color.
Watch for your own "good" labels
Everyone has clothing makers whose clothes just fit better. For me, Eddie Bauer, Ralph Lauren and Harold's seem to make clothes that hang well on me and don't need to be altered. When I see those labels, I'll generally look twice at the item because it's likely to fit well.
Feel the fabrics
Good quality clothes have a good hand feel. Get used to what top notch fabrics feel like. That way, as you work your way through the racks, you can use not only your eyes to evaluate the quality, but also your fingers.
Check the details
Make sure no buttons are missing or broken. Look for stains on the garment. If it's a shirt, check the front for dribble marks and the armpits for yellowing. Check pants for stains in the crotch (big ick!) and along the back of the leg where mud often gets kicked up. Also check the hem of pants and collars and cuffs of shirts for fraying. Make sure the seat seam of pants is intact - a surprising number of trousers get holes along the back seam. Also check that zippers are fully set, not coming unsewn at the bottom. And finally, look for loose threads or missing hems, signs that the garment may not last much longer.
Consider the cost of ownership
A $10 pure-silk blouse may seem like a bargain, but if it's dry-clean only, you will find that the true cost of owning it turns out to be much higher than just $10. Think carefully before buying clothes that needs special care or alterations. For very special items, this could be worth it, but not for most things. Also, if you see a pair of shoes or boots that need a visit to the shoe hospital, make sure they are repairable before buying them. If the wear on the heel has gone past the heel cap into the body of the shoe itself, the shoe probably cannot be repaired.
Experiment when you have time
Not every trip to the thrift store has to be about efficient use of time. When you have the luxury of an extra-long trip one day, pull out some items that catch your eye (but are not your usual style) and try them on. One nice thing about thrift stores is that you can find a variety of cuts and colors all in one place, letting you see first hand what works and what does not. So break out of the mold once in a while and challenge yourself by trying on something you never thought you'd wear. For instance, a few years ago I discovered (unexpectedly) that ribbed tops look much better on me these days than they did when I was a flat-chested teenager. Now they are a staple of my wardrobe.
Make sure it's really a bargain
Some thrift stores just don't seem to understand what thrifty means. I'm sorry, no matter how worthy the cause your store supports, I just won't pay $20 for a used pair of jeans that cost $25 new, and $5.99 for Target-brand kid's pants is more than they probably cost originally. Be aware of how much items cost in the stores so you can snap up the real bargains and pass on the overpriced stuff.
These are just a few of my favorite thrift store tips - I'd love to get your suggestions as well. And if you don't like thrift, why not? Is it the selection, the experience, the "ick" factor of wearing pre-owned clothes, or something else? What keeps you away?