When adjusting heights and clearances in the shop, accuracy is important. For example, setting up a router bit for a certain width or depth of cut is critical, and is usually a hit-or-miss process. For setting up clearances, you can obtain a nice set of setup gauge blocks, typically available in standard dimensions of 1/16, 1/8, 1/4, 1/2 inches, etc. But why pay the money when you likely have something in your shop already that will do the trick: a set of drill bits.

You can use an ordinary twist drill bit as a setup gauge. And better than the gauge block sets, drill bits can accommodate a wider range of diameters.

Here I am using an ordinary 1/4" diameter twist drill bit as a gauge block to set the cutting width on a straight rabbeting router bit.

Using a straightedge, I then set the router table fence to the corresponding distance using the drill bit. Lock the fence and I'm ready to go.