Cultural Interactions.
I think this can be the most interesting part of a trip to Thailand, trying to understand the unwritten rules of behaviour. Much has been written about this from many people but the brief version is.
Don't wear your shoes inside a building or what could be considered the private area of a dwelling. Go to take your shoes off in view of a Thai and they will tell you if it is ok to leave your shoes on or not. If they do not have their shoes on take yours off anyway.
If you have problems with your feet get a second pair of shoes or slippers for inside use. But don't wear them outside the rooms. Keep them specifically for the rooms as people often sit on the floor and are very conscious of shoes worn outside.
If you are taking your shoes off and on regularly buy a pair of slip on sandals, scuffs or slippers for general use but not in the rooms
I sat down with a group of people having a drink one evening and a Thai male came up and started stroking my leg and arm, being a male I went very tense and thought I can not disgrace myself when I have only been here a few weeks. I forced myself to relax and get to know the people and now realise it was only a friendly gesture on the part of the Thai's. Under these conditions Thai's can be very much a touchy people with the same sex. The rules of engagement change with the opposite sex, as a general rule be reserved with your interaction until you see how the Thai people interact and behave.
Patting someone on the head is insulting in almost any culture so don't be tempted to do it with someone shorter than you.
A male came up to me and asked me to dance for the first time at a village party, I was a little perturbed but did so. This is normal in Thai society for a male to ask a male to dance and since this experience I have had males in pubs ask me to dance. I politely refuse and that is also ok. It is just their way of being friendly and has no sexual connotations. In another situation a male asked me for permission to dance with my female partner. There was no problem but some females would say I don't need his permission to dance and take offence, don't this is the Thai way and you are a visitor.
Age has many unwritten rules. The young have very specific rules for interacting with older persons. With this etiquette you must show respect by wai'ing to older persons slightly longer or slightly deeper. Be careful not to be too familiar with older persons until you are sure of the unwritten rules of behaviour. Even having a joke with someone younger can backfire as the rules of behaviour prohibit the younger person from reacting in a relaxed way and you may end up stressing them unintentionally.
According to some information I read it can be bad luck for an adult to Wai to a child. This would explain the strange reaction I received from many students when I first started at the school.
Travelling home on a bus once, and we had the front seat which meant we were higher than the driver on this style of bus. Our legs were cramping so we put our feet up on the rail which meant our feet although not directly above the drivers assistant were higher than her head but still a considerable distance from the assistant . She was very distressed about this. The bottom line here is don't put your feet near a persons head or higher than their head when in close proximity to a Thai
Thai women can be very possessive so don't be too familiar with an interaction between different sexes or someone else's partner this has to be approached cautiously where as same sexes are often much more familiar with each other.
It is bad form to show emotion either positive or negative in public
For more on eating check the document What To Expect If and the Buying Foods page.