Live there some years and you will mostly find out, that we have nothing to come with. You come with food from outside Thailand, and the will be polite and taste but prefer thai kitchen or don’t afford to pay for your food. Massage ? They prefer there own. And if you’re weight is over 70 kilograms then forget it. And new ideas are maybe interesting but there is a reason why they continue with the way they do. You can’t transfer Europe idea into thai culture. But yes there is some business. But if you get it, then suddenly the market is occupied
Tips or tricks ? No reason for any kind of this if you not do anything illegal, but just are tourists as we all are, even we live there. Good behavior and respect is not wrong
you can find it under information from thai government but it must be payment to your Thai account after tax and you must have your ambassador to confirm and translated of course