One of the tips that a local can give you in San Diego, concerning shopping, is to go to an 'outlet'. As a matter of fact, they used to be called "factory outlet" stores which sell clothes and other goods cheaper than any other store. Things have changed now a lot though. Today, San Diego's outlet centers are quite impressive. They are not just scattered places, they are rather retail complexes similar to malls somehow.
However, these outlets center are still arguable.