Post-beauty treatment care in Korea: What should you bring?

I'm planning to go to Korea for my first K-beauty treatment, but I'm unsure about post-treatment care. I've heard that cooling masks and calming gels are necessary after treatments, so should I bring them from Japan?

It might be good to buy them there, but isn't it more reassuring to know what works for you? What do you all prepare, like silicone sheets? I've heard that care is especially important immediately after the treatment, so I want to be properly prepared beforehand.

For those who have actually had treatments in Korea, I'd love to know what items you brought with you and what you purchased locally. Also, I'd like to know if there was anything that was helpful during the recovery period after returning to Japan. Since it's my first time, I have a lot of concerns...