For foreigners living in Seoul, can anyone recommend some good beauty spots?

Hi! My name is Tum. I'm planning my first long trip to Seoul for beauty-related purposes. Honestly, after a very stressful work schedule, I want to try some skincare tips. I've heard a lot about Nam Island and Jujeong Appetizer. Has anyone from overseas visited these areas? What was your experience like? I understand there are many clinics and beauty salons there, but I'm confused about which area to choose.

I haven't decided on accommodation yet. Should I stay near any beauty salons, or is it okay if there's convenient transportation? It doesn't have to be luxurious, just clean and good value. Do you think 1-2 weeks would be suitable for this kind of trip? If anyone has been there, please share your experience. Thank you in advance!