In the past, hoping to get the boring mechanical bit over and done
with, I drilled my aluminium freehand, with the result that a lot
of filing then had to be done to align the screw holes of different bits.

But, now I have a drill press and an engineer's vice to hold everything
down, it's a different world!

The only skill that I have yet to master is that the bend in the aluminium
is where I marked it, and not a couple of mm distant!