Where is the best place to stay for a beauty trip to Seoul?

Hi, this is Asuka. I'm thinking of taking a beauty trip to Seoul this fall, and I was wondering where everyone usually stays?

I've heard that Gangnam and Apgujeong have a lot of beauty clinics, but what's it really like? Also, are those areas convenient to stay in? Or are there other areas you would recommend? Since it's a trip for foreigners, I'd like to stay somewhere with plenty of hotels and restaurants.

Ideally, I'd like to hear from people who have actually been there. I'd appreciate hearing firsthand accounts of which areas are quiet, have good access, etc. It's my first time in Seoul, so I don't know anything... Could someone please give me some advice?