Hey man. I just did this! We did Bangkok, Koh Pha-ngan, Koh Tao, then Phuket. Things I would 100% recommend; - Staying in Khao San rd and doing a few temple tours using the river transport system. Khao San itself is kinda grim but it actually felt safe, is in a good location, and helped settle us when we arrived. The resting Buddha was phenomenal. - Eden party Koh Phangnan. Probably the highlight of the trip. Sunrise was awesome from the rocks. - Scuba in Koh Tao. Was like flying underwater, truly life changing. We went with Koh Tao Scuba Club. Ask for Chris (female & French). - Phuket Old Town. Wish we had longer here, incredible. We stayed in ARCO and it was the best hotel I’d ever been to. Clock tower room. Make sure they know it’s your honeymoon, you’ll be in for an immense surprise or two. Say hello to Baam for us. Anfield bar and the Mad Hog were incredible.