Apples and girls from Daegu!
There's a saying that girls from Daegu have rosy cheeks cos of all the apple they eat!
If you are looking for authentic Korean art and handicraft ( not those cheap tourist items and souvenirs, you can try the Insadong district in Seoul. Some of the shops cater to tourists but there are some really good antique, handicraft and artwork shops there.
If you are more into trendy stuff like fashion, Myeongdong is good for shopping. Many big departmental stores as well as small retail shopfronts. Right now, they are having the annual Myeongdong festival every weekend until Oct 9. Lotsa of fashion shows, mini-concerts and parades. Another place where young people hang out is Sinchon, they have lotsa pubs, restaurants, hobbies shops, art galleries and photo studios there. You can get some really creative photo art there.
And you really can't find anything else to buy, at least the ginseng is good!^^