Taboo in Tibet
some basic etiquette rules that should be followed when in Tibet include:

Never touch the head of a Tibetan, the head is considered a sacred part of the body.
Show proper respect in the temples, don't wear noisy shoes, drink alcohol, smoke or make unnecessary noise.
Don't put your arms around someone's shoulders.
When visiting a temple, follow the pilgrims and circle the tmeple clockwise, never counter-clockwise.
Never touch, sit on or walk over any religious items such as prayer flags or texts.
Don't kill any animals or insects in monasteries.
Don't be intrusive during religious ceremonies, this means be respectful when taking photos.
Don't harm animals wearing red, yellow or green cloth.
Don't step on the threshold of Tibetan homes.
Don't spit in front of people. Don't throw garbage into a fire.
Don't engage in strong displays of public affection.
Dress modestly.