The weakest shopping area on the island, most shops in the west coast resorts are geared almost exclusively to tourists and to the work-a-day needs of residents, so you'll find washing machine parts and ironing boards but scant regard for jewellery, shoes or fashion.
The best supermarkets are at Playa de la Arena and Playa San Juan.
There are two regular markets along the west coast. At Alcalá (Plaza Del Pueblo, Mon 9am-2pm) vendors sell local produce, crafts, jewellery and household goods and at Playa San Juan (on the TF47 main road between Los Gigantes and Costa Adeje; Wed and Sun 9am-2pm) fruit, vegetables, flowers and plants join the rows of clothes and household goods.
Los Gigantes is in Tenerife. For general advice on shopping in Tenerife, see my Shopping in Tenerife page.