Thai people have a deep, traditional reverence for the Royal Family, and a visitor should be careful to show respect for the King, the Queen and the Royal Children.
Visitors should dress neatly in all religious shrines. They should never go topless, or in shorts, hot pants or other unsuitable attire. It is acceptable to wear shoes when walking around the compound of a Buddhist temple, but not inside the chapel where the principal Buddha image is kept.
Each Buddha image, large or small, ruined or not, is regarded as a sacred object. Never climb onto one to take a photograph or do anything which might indicate a lack of respect. Buddhist monks are forbidden to touch or be touched by a woman, or to accept anything from the hand of one. If a woman has to give anything to a monk, she first hands it to a man, who then presents it.
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.
Beware of unauthorized people who offer their services as guides. For all tourist information, contact the Tourism Authority of Thailand.
Observe all normal precautions as regards to personal safety, as well as the safety of your belongings. Walking alone on quiet streets or deserted areas is not recommended. Be sure that all your valuables-money, jewelry, and airline tickets are properly protected from loss.
Drop your garbage into a waste container. The Bangkok Metropolitan Administration strictly enforces the law in an effort to keep the city clean and healthy. The fine will be imposed on a person who spits, discards cigarette stubs, or drops rubbish in public areas.
Do not get yourself involved with drugs. Penalties for drug offences are very severe in Thailand.
Do not support any manner of wild animal abuse. Never purchase any products or souvenirs made from wild animals including reptiles like snakes, monitor lizards, and also turtle shell and ivory. Avoid patronizing local restaurants that serve wild animal delicacies. It is against the law to slaughter wildlife for food in Thailand.