Community prompt: What should foreigners check before renting in Seoul?

Experience

This is a Settly Team starter question for the Seoul community, not a user-submitted story. If you have handled renting, deposits, management fees, heating, move-in checks, and neighborhood tradeoffs in Seoul, share the detail another foreigner would need. Helpful answers include neighborhood or station, visa or stay type, timing, approximate cost, documents, place or office visited, what blocked you, and what finally worked. Do not include passport numbers, residence numbers, bank details, reservation codes, exact room numbers, or private contact details. For visa, tax, medical, or legal decisions, check official sources before acting.