Consignment stores and other resellers are the easiest and quickest ways to turn old clothes into cash. It's important to sell the items as close to the season as possible. A winter coat will not command the same price in July as it will in November.
Resellers will not accept clothes that are not in good condition. The items should be free from rips and stains. They should also be clean. Some resellers only provide store credit, while other stores offer cash in exchange for the new inventory.
Some clothes may be rejected by the reseller. Ebay and Craigslist are options for selling used clothes online.