In the RS guide, he describes a walking tour that starts in front of the Catedrál, proceeding to the right, or towards the Ramblas. That side street comes to a fork at a wedged shaped building. To the right is a great olive oil shop where you can taste mild, medium and strong olive oils. Yum!
If you take the left, you end up on Banys Nous. There are some artisan shops. We found a delightful merchant at #17 who sells crocheted, metal jewelry. The artist, she claims, is diminutive in size, but has strong hands, as she can crochet the various colored ultra thin wires into such delicate structures. Name of the store, to give it a plug, as Rick gives the olive oil store a deserved mention, is Dactilar, Banys Nous 17B. The proprietor speaks a bit of English, whom we found charming.