Learn at least a few words of the local language. Local people will respect and appreciate your efforts. If you wish to photograph local people and their homes, please ask their permission. In some instances you may be expected to pay for the privilege. If you are refused permission, respect the decision.
Hand holding or kissing in public can cause embarrassment or offence in some countries.
Care must be taken in some areas where tribal people's immunity to outside diseases may be poor. Always ask permission before entering tribal people's territories, and pay properly for their services or handicrafts. On set tours, check with the organisers that communities have agreed to the visit and are expecting your group. Avoid displays of conspicuous consumption - expensive jewellery, watches, personal stereos. Apart from possible incitement to robbery, it accentuates the gap between rich and poor and distances you from the cultures you came to experience.