Getting a facial treatment in Seoul, planned properly
Most of the decision is a calendar problem: what recovers in time, what needs a second visit, and what should wait. Start with the planner.

Timing
What fits your dates, and what has to wait for a longer trip.
At the clinic
How a visit runs, what to ask first, and what to take away with you.
Language
The words you will need before and during the appointment.
Myeongdong
The district the clinic is in, and what a visitor needs to know about reaching it and finding their way around.
Travelling from
Flight length and time difference change how the first day of a trip should be used.