Carrie Kirby, an Oak Park mother of three and the author of the Chicago Tribune column Frugalista, buys nearly all of her kids' clothes secondhand - including their underwear.

When it comes to searching for gently used finds, Kirby says many people confuse thrift shops with resale stores.

"I think of my shopping options as a spectrum," she says, "from the cheapest thrift stores to rummage sales, consignment events, eBay auctions, and then on up to the higher-end resale shops."

Children's resale and consignment is big business-nationally, and here in the Chicago area. According to an industry trade group, the number of resale/consignment shops has increased at a rate of about 7 percent annually for the past two years to more than 30,000 stores in the U.S. Some stores work on a straight consignment model, others buy the merchandise outright and some use a combination of approaches.

Kirby shares some tricks of the trade:

• Look at the end-of-season and clearance stuff first.
• If you don't see what you need, ask the store clerks-they have piles upon piles in the back. If you shop regularly at a store and get to know the staff, they will be more likely to help you out.
• Ask if the store offers a better rate if you pay in store credit rather than cash.
• Don't overlook other places where you can get great deals, like consignment events.

Kirby reminds sellers and consigners to keep the following in mind when they try to sell their items:

• Don't take it personally if the store doesn't accept everything. Space is limited and they have to be selective.
• If a store doesn't take an item, ask why. Maybe that particular store just has too much of that type of clothing and you could bring it to another store to see if they might be interested.
• If you're looking for some quality second-hand duds or gear for your kids (or looking to get rid of the unused items cluttering your closets), give one of these first-rate local shops a try.

Here are five resale shops we're raving about. Do you have a favorite? Comment below!