Understand the size scales. American women should move up two dress sizes, and add one and a half to their shoe size.
Learn the new lingo. Charity shops and dress agencies, the British equivalent of American vintage and consignment stores, have the biggest selections.
Stroll King's Road West, where you'll find an array of charity shops. Tucked within the facades is the most celebrated London vintage shop, frequented as much by socialites as students.
Check out some of the many London markets. Covent Garden, Portobello Road and Camden Passage are must-stops for accessories and jewelry, as well as clothing.
Keep in mind that prices may be a little higher than you're used to paying for secondhand garb. You'll get what you pay for in terms of unique and authentic period pieces; just be prepared to lay down the plastic.
