Which island are you going to? Oahu or the other islands?
Well, in Oahu the standard mall is Ala Moana, right next to Waikiki. It has a lot of the commercial stores that you’ve already been to, but there are a few there that are only in Hawaii: Luxi, Le Lotus Bleu, Jeans Warehouse, etc that range from expensive to cheap. Other malls include: Kahala Mall, Pearl Ridge Shopping Center, and Windward Mall.
Also, Waikiki has some good shops on the strip, but you’re going to go a little off the beaten path for them (i.e. down a few streets, up flights of stairs) or you’ll miss them. Pineapple County is pretty popular as is 88 Tees.
As for shops that are around Oahu there is Butik, Bamboo Sky, Chic Icon, etc.
Also, hit up our local flea market, the Swap Meet, at Aloha Stadium.posted over 4 years ago