Social Norms : Thais don't normally shake hands when they greet one another, but instead press the palms together in a prayer-like gesture called a wai. Generally a younger person wais an elder, who returns it.
Thais regard the head as the highest part of the body, literally and figuratively. Therefore, avoid touching people on the head and try not to point your feet at people or an object. It is considered very rude.
Shoes should be removed when entering a private Thai home.
Public displays of affection between men and women are frowned upon.
Although almost all year round in Thailand has a hot weather, walking shirtless on the street, especially in Bangkok, is generally regarded as impolite - tank tops are acceptable