sink cut out

Back again, still working on my first job. What is the proper procedure for cutting out the sink hole for an undrmount sink? I assume after cutting the piece, I rod first. Mark my piece with the template cut all the straight lines and (http://maplered.com) the straight cut the corners. Then make scisor cuts into the rounded parts, grind and (http://maplered.com) chip out the excess, and (http://maplered.com) polish?
Do I cut it out from the polished side or rough side, or does it matter? Is there a tool, drum, grinder for making the rounded corners of the sink easier. thanks steve
Stone (http://g603.net) st. cecelia, manual fabricating