I have used my Rotozip for several projects but not for cutting drywall openings for outlet boxes and recessed lighting fixtures. In particular, I have 16 recessed light fixtures that need openings in 5/8" rock used on my remodeled basement ceiling. I have Rotozip bits used for cutting around boxes, but am a little unclear about the techniques I need to use. Should I position the ceiling rock with no openings and plunge to "center" of the fixture, then work my way to the edge and then around the perimeter? Or should I measure and cut small openings that approximately fit center of the fixtures and then use the Rotozip to accurately complete the cuts when the rock is positioned on the fixtures? Thanks in advance for your advice.