Do NOT in anyway shape or form say or do ANYTHING that would be considered as being injurious to the dignity of the royal family. This includes but is not limited to saying anything bad about the king, stepping on or defacing Thai money or anything with the image of the King on it.
The Thais love their King. Remember this and act accordingly.
Don’t raise your voice or show anger. This has to do with face and if you cannot control yourself you will look like the ignorant tourist you really are.
Don’t hurt anyone especially a Thai. You will be held responsible and you really do not want to have to deal with the Thai police. It will cost YOU.
DO Smile A LOT and enjoy your trip.
Anyone else have suggestions in this vein, please feel free to add comments. They are most welcome.