Drilling a hole that is exactly perpendicular to a surface is easy enough if you can fit your workpiece on a drill press. But keeping your handheld drill at a perfect 90° is challenging, especially when working toward the center of a wide surface. To help with this, I made a drilling guide by clamping a steel spacer in a handscrew with a V-notch sawn into one of its jaws. To make your own, cut the notch at the table saw and use the reassembled handscrew to hold a spacer whose inner diameter just accommodates your drill bit. My local hardware store carries these spacers in 2" lengths with inside diameters ranging from 1/16–1/2".
—Richard Entwistle, Highland Lakes, NJ