Tipping
Tipping is not generally part of Thai culture, so it’s not expected, but in tourist centres many workers have got used to this Western habit and are not averse to receiving a token of appreciation for efficient service.
There’s certainly no need to calculate a percentage of costs as in the USA, so tipping in Thailand is a more relaxed activity. You might like to let taxi drivers, wait staff in restaurants and bartenders just keep the coins in change from a bill, though if the service is more extensive, such as tour guide for a day, something like B100 would be more appropriate.