Do:
Say "Sawasdee Krab" for men or "Sawasdee Ka" for women when greeting Thai people.
Perform the 'Thai Wai", a slight bow with the palms pressed together in a prayer-like fasion, while saying "Sawasdee Krab" or "Sawasdee Ka".
Use "Khun" as the honorific title before a person's first name .
Always respect the elders. If someone is older than you, address them as "Pee" or "Nong" if they are younger.
Speak softly and smile warmly.
Respect the places and dress appropriately when visiting temples and religious sites.
Always treat any image of a Buddha and Buddhist monks with extreme respect.
Always ask for permission before taking pictures of anyone.
Avoid kissing or hugging in public.
Remove shoes before entering a Thai home.
Try to learn a couple of Thai words and phrases.
Do not:
Express negative opinions about the King or any member of the Royal Family. Thai people have utmost respect for the Thai monarchy.
Pass anything with your left hand and point with one finger.
Get involved in anyway with drugs. Penalties are very severe from 10 years up to the death penalty for trafficking.
Point at people or things with your feet.
Touch a Thai person on the head.
Raise your voice or get angry as it is a sign of disrespect in Thailand.