If you want to get the most money and bang for your buck, you might want to look into a consignment specialty sale. Around here we have one called Ring Around the Rosy, and I'm sure there are similar ones across the country. RATR happens 4 times a year, and you have to rush to get a spot as a consignor. Not only do you get your stuff consigned, as a consignor you get a preview day to shop. And you can choose to have your stuff pulled for return before the half price days, or after the half price, or just donated at the end. They take care of all of the marketing, sales setup, tracking, etc, and help with pricing.
Outside of that, your best bet is to sell the clothes in "lots". Your price per item will be lower than the top price you'd get, but you'll get less hassles on price (or at least more room to maneuver) and end up with higher over all. Sell a set of clothes that go together somewhat, in the same size.
at 10:46 PM on May. 31, 2011