Base yourself at the Sonesta Fort Lauderdale Beach. Its location at the corner of A1A and Sunrise Boulevard gives you a number of driving options in visiting thrift shops and consignment stores scattered around the county.
Spend the morning at the Festival Flea Market Mall up in Pompano Beach, about 15 minutes from Fort Lauderdale. With over 500 merchants in booths, boutiques, specialty shops and pushcarts, Festival draws crowds from everywhere, many shoppers coming by tour bus. Indoors in what used to be an outlet mall, it's good shopping no matter what the weather outside. There's a food court if you get peckish.
Head back to Fort Lauderdale and Wilton Drive for a lunch break on the patio of Rosie's Bar & Grill. Before tying into a burger, wrap or salad, order a Big Helga, a gigantic pretzel appetizer served hanging from a rack. It has parking for patrons, but there's also free parking a couple of blocks away behind City Hall if you plan shop before or after lunch.
Down the street from Rosie's is Out of the Closet, one of two in Fort Lauderdale, and Boomerangs. The first benefits AIDS, the second animal rescue, but both are well organized and well stocked with clothing, furniture, books and thrift shop treasures. Out of the Closet displays its bigger canvases and prints art-gallery style. On the other side of the street is Some Men Like it Haute, an upscale consignment shop that looks like a boutique. Note that Tuesday through Thursday, it closes for lunch between 2 pm and 5 pm and doesn't open until noon Friday through Sunday. Doug, the shop's owner, also has a 4-unit apartment rental nearby and is a good source of shopping tips.
If you have time and energy left, hop back in the car and drive a few minutes to the Poverello Center, serving the HIV/AIDS community and financed by its thrift shop, which has an almost overwhelming assortment of goods as well as an eBay store. There's a large parking lot in the rear. The last stop on your thrift treasure hunt is the other Out of the Closet on Sunrise Boulevard across from the Gateway Theater. From Poverello go to Federal Highway (US 1) and head south. Immediately after Federal Highway takes a bend to become Sunrise, turn into the Out of the Closet parking lot. It's easy to miss even though the bright pink-and-turquoise building isn't.