We always fly into Bangkok and give ourselves two full days to explore the city. Check out the palaces and take a boat ride down the Chao Phraya River to see most the highlights more conveniently. Try to get reservations at Gaggan if you are feeling fancy while you are there. It is INSANELY amazing. Book a roundtrip ticket from Bangkok to Ko Samui on Bangkok Airways (this is one of our favorite little airlines of all time...super affordable and always on time.)
It is very convenient to book a combo ticket that will include your transfer from the airport to the pier and your ferry ticket to Koh Tao. You will leave from Bangkok, take an hour flight to Koh Samui, get picked up at the airport and take a 30 minute ride to the pier where you will get on board the boat to the islands. (The ticket just includes the catamaran and dock transfer. We would recommend the high speed Lomprayah ferry). They make one stop on the way there (Koh Phanagan) and then the next stop is Koh Tao. It is worth the extra stop! Wave goodbye to everyone as they get off one island short of paradise.
Book a Villa that can pick you up from the port and take you to where you are staying.
Sunscreen and BUG SPRAY. Yep, you will want the “real deal” in both scenarios. Have dramamine ready for your boat ride out there! Nine times out of 10 it’s perfectly smooth but yes, it is possible you might be met with rough waters.
When you land in Bangkok, grab a SIM card for your phone. It will cost about $20 for unlimited data. You will WANT this to navigate around Bangkok and more importantly Koh Tao!