What procedures do I need to go through at the airport when traveling abroad?

1 Make sure you are in T3 or T2 terminal

2 After going to the airport, go to the ticket exchange point where your airline is located and use your passport to exchange your ticket first. Check your luggage at the same time. Ask if you are in the same terminal in Korea and if they will transfer your luggage directly to Phuket. Usually.

3 Take your ticket and go to the customs (if you ask the staff, he will tell you that you should go and get it next)

4 When the customs goes: check your passport (visa) air tickets.

5 When entering customs, your hand luggage and personal belongings will be checked

6. After passing customs, you will go directly to your boarding gate, even if you have nothing to do. If you have time, you can visit duty-free shops.

7 Boarding

8 Transfer: The ticket you bought should not leave the terminal where you landed. You can directly find the boarding gate of your second ticket. The second security check is usually near the boarding gate.

(Not necessarily in each country, maybe like China, you need to go through their customs again before boarding the plane, but the steps are the same)