I found a useful item in the package of my subwoofer - this nifty little foot point. I rolled a couple of them and this was the most on center at less than 1/128" off center on the tip. I now slip it into the chuck, align the point on the center punch divit or at the crosshairs of where the new hole is to be drilled, swap out with the bit size of choice, and drill. a great tool tip for those who don't have access to Norm Abrahm's laser aligned drilling machines!
here it is in action, shown with the point about 1/32" down into the center puched location for the first of four neck mounting holes I needed to drill last night
this has certainly improved my 'freehand' drilling accuracy, not to mention that I've also been able to significantly speed things up as I no longer spend forever and a half jiggering the alignment of the drill bit tip to get it spot on
all the best,
R