For accidents with injuries:
Call police, remain at the scene.
For non-injury:
i think the most important detail to take down is the other party's
license plate, because everything else can retrieved from it. If
possible, take the driver's IC details too.
Then visit the nearest IDAC for them to record down the damages to
your vehicle. I believe they will ask for your vehicle insurance
details which you should have in your vehicle and should help you
with your claim form.
Finally, confirm with your insurer where the vehicle should go for
repair, give them a call.
Things not to do:
1. Do not bother arguing with the other driver, absolutely nothing
is accomplished
2. Do not attack the other driver