Culture, customs, and things you should know to not offend the locals
The culture of Thailand is heavily influenced by Buddhism. About 95% of the Thai population are Theravada Buddhists.
Greetings
Thais greet each other using the wai, which is a greeting with your palms together (have the bottom of your palms at about your heart level) and a slight bow (bending your head down), and saying 'sawatdee kha/khrap' (kha if you are female, khrap if you are male). It is also used to show respect and as a goodbye salutation. The hard thing is knowing when to wai. You should wai to an equal/peer, elder, superior, but not to children.
Look, Leonardo DiCaprio can do it!
Temple Etiquette
Dress neatly (no sleeveless shirts, not shorts..preferably trousers or sarongs with knees covered), take off your shoes before entering a wat. Women, do not touch the monks — if you want to give something to a monk, place it on a table within the monk's reach or the like. If you sit down in a temple, sit so that your feet are underneath you and pointing backwards (ie. do not point your feet at Buddha statues or images). Make sure the soles of your feet are not pointing at the altar or Buddha images. It is considered good luck to walk clockwise around the temple. Do not climb on any Buddha statues…you'll get into big trouble.
Feet and Head
Feet are the lowest part of the body spiritually and considered dirty. Don't point your feet at anything or anybody. Don't prop your feet on chairs or tables while sitting. Don't touch any part of someone else's body with your foot.
Heads are the highest part of the body spiritually. Don't touch people on their head or Buddhas on their head. Don't sit on pillows meant for the head. Don't step over anyone (ask them to move). Don't step over food.
Shoes
Take your shoes off before entering a temple or someone's home — you may see a pile of shoes by the entrance. If you see a pile of shoes in front of a shop, guesthouse, etc, take your shoes off.
Dress
Shorts (except knee-length walking shorts), sleeveless shirts, tank tops, beach attire is not appropriate dress (only at the beach).
Emotions
Try to refrain from showing anger or impatience. Do not raise your voice at a Thai person. It is very rude and disrespectful.
The King/Royalty
Never disrespect the King or the royal family…or you may see Brokedown Palace with your own eyes…
Monk's Morning Alms Rounds (Bindabaat)
In the early mornings, the monks collect alms — donations of food. If you wish to contribute to alms, you should do so respectfully. If a monk is approaching you, say "nimmon". He will open the lid of his alms bowl. Then you carefully place the food, one after another, into the bowl. Monks collect alms barefoot. For women, the monk may have a receiving cloth — put the food in the receiving cloth. When you offer alms, you should take your shoes off out of respect (leaving your shoes on notes that you are a higher rank than the monk), and kneel down and wai.
An account of bindabaat from an expat's point of view can be found in this article (a good read).
A note on what is above…I took that from info gathered on various websites. I spoke with my mom, who says that you do not have to take off your shoes or crouch all the way down. She says that you can bow down and wai. She said that mostly the older people take their shoes off, crouch all the way down and wai. My thoughts — watch the Thai people and do as they do.
