The simple guidelines below is taken from an old information board issued by the Tourist Authority of Thailand, pertaining the do and don’ts. These guidelines are similar in most Asia countries:
Don’t climb upon the Buddha image to take a photograph or do anything that might show a lack of respect
Do dress politely in public places.
Don’t go shirtless, or in shorts, hot pants, or other unsuitable attire inside the temple.
Do wear shoes while walking around the compound of a Buddhist temple but don’t wear them inside the chapel where the principal Buddha image is kept.
Don’t display affection for any other person in public. It is frowned upon in the Thai society. You may hold hands, but that’s as far as it goes in polite society.
Do ‘wai’ when greeting another person. Generally, a younger person was an elder, who returns it the same gesture.
Don’t touch the head of another person, even in a friendly gesture. Thais regard the head as the highest part of the body both literally and figuratively. It’s considered rude to point your foot at a person. Don’t point your foot to show anything to anyone, but use your finger instead.