PCB drill with an USB microscope as visual aid
Single-sided PCBs are relatively easier to homebrew. Holes for PTH components can be drilled with a reasonable accuracy without any sort of visual aid. However, if you want to make double-sided PCBs with strict drilling requirements, eyeballing might not be enough to drill holes at precise locations. This Instructable is about making a USB microscope guided PCB drill to achieve better accuracy in drilling holes in PCBs. Unlike regular drills, this machine drills holes from bottom to top.
PCB drill with USB microscope as visual aid