Some interesting customs I observed in Thailand with which you are undoubtedly familiar included the wai (hands placed together and pointed at the chin, nose or forehead with a bow depending on the status of the individuals involved). Small children would place their hands together at their foreheads and bow low to an elder, for example, while peers would place their hands at their noses and blow moderately. Elders would place their hands at their chins and bow slightly to younger individuals. This was a wonderful custom I thought (since I have grown older, I like it even more!).
Another custom involved pouring soft drinks into plastic sandwich bags and tying them with a rubber band to be hung from some handy spot (such as a door handle or a finger); this allowed the merchant to keep the glass bottle and the deposit.
Finally, I loved the way the Thais decorated every-damn-thing with color. They hang strands of flower petals everywhere such as from their rearview mirrors in their "baht buses," which were also painted in wildly colorful ways. All in all, a very carefree people who are clearly wise about what is important in the world.