All hotels, and many outside restaurants, automatically add a 10% service charge to your bill. However if the restaurant staff give you good service, adding a further 5% will be appreciated, but it is not mandatory.

If no service charge is added, a 10% tip is sufficient.

Porters should be tipped IDR5,000 per bag (or US$1 if you don't have local currency on you at the time), and you should "round up" and add IDR1,000 when paying a taxi driver.

It's unnecessary to tip housekeeping staff at your hotel, unless you ask them to bring you extra towels or similar, in which case you should tip them IDR5,000 (or US$1).