If you're looking for fun and interesting places to go for shopping in Cuzco, Peru, many of the locals will tell you to check out Cuesta San Blas and the Hatunrumiyoc. As tourism is an important aspect of Cuzco culture, there are several great places to find authentic Peruvian trinkets and apparel on these streets.
Cuesta San Blas is a street that ascends a large hill in Cuzco, so it's probably best to start from the top at Plaza San Blas, and meander down the street, stopping at places that seem interesting to you. One great place to check out on Cuesta San Blas is Centro Artesanal Sambleño, as you can find authentic hand-crafted Peruvian jewelry and souvenirs.
Hatunrumiyoc also offers a veritable selection for shopping in Cuzco. One of the most notable is the stand located in front of Cuzco's famous 12-sided stone, which used to be part of the palace of Inca Roca, and is now inconspicuously located in one of the walls on this street. The stand sells great jewelry and apparel, and is a staple in the neighborhood. Hatunrumiyoc is also on a steep hill, so be sure to wear comfortable walking shoes and start from the top.