Dress, shoes, the wai, and two genuine red lines
Thai temples are working places of worship rather than museums, and visitors are genuinely welcome. The rules are simple and a little care goes a long way.
Women should not touch a monk or hand anything directly to one — put the item down and he will pick it up. It is part of his vows, not a slight.
Palms together at the chest with a slight bow — greeting, thank you and respect in one gesture. As a visitor nobody expects you to get the fine points right. Two rules cover it: return a wai if you are given one, and do not wai children or service staff, where a smile and a nod is correct. Keep your hands at chest height and you will never be wrong.
Generally fine. Ask before photographing monks or people praying, and no flash indoors. Posing playfully with Buddha images — arm around, peace sign — causes real offence.
Two lines that matter more than any of the above. Buddha images are sacred rather than decorative, so tattoos and souvenirs treating them as ornament are genuinely resented, and taking images out of the country is restricted. And the monarchy is protected by strict law — not a subject for jokes or opinions, in person or online.
We live here — ask us anything about Hua Hin and you will get the real answer.