Thailand is a tipping country, so tipping is normal. Tipping people who help themselves will give them a sense of accomplishment that their self-worth is affirmed, and the following service will be harder and more meticulous. So if you travel freely, if the service is good, it is recommended to tip 20 baht, up to 50 baht. Be careful not to give coins when tipping in Thailand, because coins are for beggars.