Respect the local customs & religions. Customs vary between the different ethnic groups in this region so just be observant. Every morning at 8 am and in the evening at 6 pm loudspeakers throughout Mae Sai blast the Thai national anthem and an ode to their King. Everyone stops in their tracks when the loudspeakers errupt, TV broadcasts & radio broadcast are interupted and it would be wise for you to stop what you are doing only for a moment.
Most people coming to Thailand for a visit know, or at least read up on, the cultural do's and don'ts of Thailand & her people. I'll use this space to write a bit about a horrifying sight we saw on our family trip to Thailand. I was disgusted at what I saw and felt sorry for the Thai and Burmese people who saw the same thing I did. Prior to getting up to Mae Sai we had stopped for a few days in Chiang Mai. One night as we walked around the night market a German woman and her boyfriend passed us by on a crowded, narrow sidewalk. As the tall, blonde German woman passed thru the crowd heads truned and most people had a look of shock on their faces. As she passed me, my friends, and our family I could see why she was such a spectacle. She was wearing a completely sheer (see thru) black top which totally exposed her breasts. This statue of a woman, with her short cropped blonde hair had obviously forgotten to read about the do's and don'ts of Thai culture before walking the streets dressed as she was. Have some respect. To my shock we saw her again (obviously she was on the same circuit as we were) walking from through the markets in Mae Sai wearing the same see thru top with no bra.