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

I finally have some free time, so I'm planning to go to Seoul to do some beauty-related things. I've heard that there are a lot of beauty clinics around Gangnam and Apgujeong, but what's it really like?

Also, I'm wondering which area would be most convenient to stay in. Should I stay near the clinics? Or would it be better to stay somewhere else, combining it with sightseeing? Where do people who are foreigners visiting Seoul for the first time usually stay?

Honestly, I don't know Seoul very well, so any advice would be greatly appreciated. Also, any personal experiences, like things to be careful about on a beauty trip, or areas you enjoyed, would be incredibly helpful. Is there anyone with experience?