Thailand is a popular tipping country, generally starting from 20 baht (about 4 yuan dollars). In principle, all service industries can accept tips, including Michelin.

But giving or not is voluntary. I was in Thailand for 7 days on May Day and only gave it once. The taxi driver to the zoo is very enthusiastic.

Tour guides also ask for tips. I think they speak too much English and too little Chinese, so they don't give any.