Hey foreign ladies, which area in Seoul is the best for a beauty trip?

My name is Hanh, and I'm planning a trip to Seoul for some treatments. I've heard that Gangnam and Apgujeong are famous for beauty services, but I'm a bit confused because there are so many options and I don't know which area is really convenient for a foreigner like me.

Do any of you have experience with beauty trips in Seoul? Which areas do you usually stay in? I'm looking for accommodation near clinics/spas for easy access, but I also want places to eat and shop. Are Gangnam or Apgujeong really better than other areas? Or are there any other areas you recommend?

Also, I'd like to know whether it's better to stay in a hotel, hostel, or Airbnb? My friend is worried about staying alone, so any advice from experienced travelers would be greatly appreciated. I'm trying to be flexible with my budget, depending on the quality of service and location. Anyone who has been on a beauty trip to Seoul, could you share some tips?