Prior to our trip, I contacted Korean Air with our flight information and asked if we could have a complimentary room. We quickly received a response confirming that we had a free night in one of their partner hotels in Incheon. The exact hotel would be determined upon arrival and check-in at their easy to find kiosk within the airport. It was that painless!
After our flight landed in Incheon, we went through customs and then went directly to a help desk in the main terminal. She pointed us in the direction of a specific convenience store within the terminal that sold Seoul CityPass+ cards. These cost 2,500 won (about $2.50 USD) and allow you to load money onto them to pay for subway rides, buses, and taxis. On our way through the airport, we loaded the cards at easy-to-use kiosks just before the entrance to the subway. We each put about 10,000 won (just under $10 USD) on our cards.