Have you ever visited Gyeongbok Palace? Did you know that if you visit while wearing Hanbok, that it's free entry? It's also free at the other palaces too (just double check on their web site to find what days they're open before you visit).
I brought my son (who's bilingual in English and Korean), and we rented Hanbok to do just that. I'd recommend trying this at least once because it's a fun experience.