Originally Posted by Nemo de Monet
Practice, and luck. (What was it Yogi Berra once said? The more I practice, the luckier I get...) Also, always do the front panel first. Nobody really cares what the back looks like, so if you really screw the first one up, you get a second shot with the other panel. (With tube amps, you can always claim any "extra" holes in the back are for "ventilation"...)
I put 3 tiny pieces of electrical tape on one side of the PCB, this is holding it in place nicely. Who would have thunk it?
I'm going to declare my drilling last night a success. I got everything drilled out nicely except for the top. The top has a small hole in it but I did not want to push my luck with the sketchy drill bits I currently own. I'm buying a stepped bit this weekend and asking my neighbor to borrow his drill press so I can finish the top.
My new "technique" consists of putting masking tape over the piece I'm about to drill, then drawing on it to find the right spot for drilling. Right afterwards, I stare at the piece with my OptiVisor for 5 minutes from all angles to make sure the holes will be in the right place. I lay out the volume knob and any other bits in the proposed area to see if the layout makes sense. I use a center-punch to set the holes so my drill doesn't "walk", and always drill a small pilot hole to get started. For aluminum you can use a knife to deburr the holes.