Australian rules are (we keep left and go clockwise around roundabouts)

• If turning left, indicate left throughout the entry and exit
• If turning right, indicate right, indicate left after the exit before the one you are using
• If going straight ahead don't indicate on entry, indicate left after the exit before the one you're taking

I'm sure most people follow the rules, but I see a lot who indicate wrong, and the drivers of the various premium brands don't indicate at all ever