It took several attempts to figure how to easily make a semi nice looking hole for the selector knob of the under $4 Harbor Freight Volt Amp Meter.
EZ - PZ!
First take a 2 x 4 and clamp it in vise, then screw the box to the end-grain of the 2 x 4.
I am placing the screws where they will not interfere with my circle cutter.