#1 Being Ignorant
The first rule when you are in Indonesia is “never be ignorant” to people. Show your kindness to all people like how they greet you. When they greet you, they must be smiling. That is the most difficult multi-tasking job. But what you will see is natural. That is very common in Indonesia.Indonesians are collectivist. They love gathering, having small talking or discussion, and asking some questions - even it seems personal. That kind of phenomenon is also very common. If you are from individualist culture, having deep understanding of cultural diversities is needed. Therefore, try to greet people before they greet you - if it is possible. Showing your smile then say hello is not that difficult.
#2 Flat Expression
Indonesians always smile. They try to convey their friendliness. They even greet you even while they are riding or driving. They always try to find an opportunity to talk to you and ask you some questions - even some of questions sometimes seem too personal. Those are the way we greet foreigners. We love making friends. Responding those phenomenon, thing you need to do is very simple - show your smile as a sign that you respect Indonesians. In other words, don’t be flat. That is not so difficult, isn’t it?!
#3 Behave Like in Your Country
This point intersects with terms so called cultural diversities and cultural practices. Not all your habits, which are acceptable in your country, are acceptable in Indonesia. I suggest you to take your time to observe the way people behave, the way they interact, the way they talk (non-verbal behavior), and the distance they create in interaction (proxemics).
#4 Proxemics
I have an interesting experience regarding this point when I accompany someone from Philippines. At that time, she is always - reflexively - be in between my intimate (6 to 18 inches) and personal territory (somewhere between 1.5 feet to 4 feet). So, when talking to people, always keep in your mind that although Indonesians are collectivist, you should not physically too close to them when interacting.