Touching others – In the northeast and other traditional areas, small towns especially it is not acceptable behavior to touch your significant other in public. If you do so you and your partner will be talked about as if you found each other in the prostitution districts of Pattaya. In Pattaya, Patong, and other areas known for catering to the sex-tourist touching your partner in public is rather OK. At least it’s done often and there’s not such a big issue about it. Please don’t force a Thai person to behave according to your western standards when in their home town. It will cause a real loss of face for them and their family as it will be the talk of the town.
Touching someone on the head – even a child, unless you are a good friend is something that shouldn’t be done. The head is the most respected part of the body and it’s disrespectful to touch anyone there.
Pointing feet – The feet are the dirtiest part of the body and even pointing your feet at someone while seated or laying down might be taken as a sign of disrespect similar to westerners showing the middle finger. Refrain from this!
Bare feet inside the home – Remove your shoes before entering anyone’s home and also before entering a business if you notice shoes outside the door.
Thai men staring – Thai men and women stare at foreigners a lot, especially in the smaller cities where they don’t see many tourists. Thais do not stare for malevolent reasons. As a male you may feel like someone is confronting you by staring at you. If you smile at the Thai person he or she will likely laugh embarrassed that you caught them staring. They stare out of sincere interest, not because they mean you harm. Unless you did something horrible, and then you’ll probably know why the person is staring!
The wai – Wai-ing someone older than you when you meet is very important in the northeast and you will gain a lot of face if you learn how to do it correctly and when to do it. Ask a Thai person to show you the correct way to wai as it will endear you to the Thai people you interact with during your stay.
Blowing your nose – Thais don’t blow their nose loudly. Usually they don’t blow at all. They wipe. Blowing your nose loudly is quite obnoxious to Thais and you’ll not gain any friends for it.
Using a toothpick – Cover your mouth with one hand and pick with the toothpick with your other hand. It’s rude in Thailand to pick your teeth without covering the process so others can’t see it.
Eating your food – Thais eat primarily with a spoon. They eat everything with a spoon, whether it makes sense or not. The fork is used only to help food onto the spoon. If you want to fit in you’ll ditch the fork and do your best with the spoon.
Speaking Thai – If you know a little bit of Thai you should always be adding “krup” if you’re a male, or “ka” if you’re a female to the end of everything you say. Thais love it when foreigners care enough to be polite when they speak Thai. You will likely get many compliments if you speak this way.
Accepting something from a Thai – If you are offered a drink from a Thai man, you probably should accept. It doesn’t matter if you don’t drink at all – you probably should accept because the person offering you the drink is probably trying to build face among his friends or those watching. If you turn him down, face is lost. Not a good thing! Especially during Songkran (Thai New Year) or other situations where the Thais are already drunk it’s a really good idea to accept a drink and if you don’t want to drink continuously with them – thank them profusely and move on.