The best traditional shopping can be found in the towns alnong the Bothnia Coast; Skelleftea, Pitea, Lulea, Kalix and Haparanda-Tornio (where IKEA is established).
If You´re interested in local and Sami crafts I recommend Arvidsjaur, Arjeplog or Jokkmokk. The Sami word for handicrafts is duodji. It´s also a quality sign for true Sami handicraft.
Flee markets and Second hand stores can be found in all towns and villages in the area. Street markets and fairs in all towns at special occations.