Locate cut-outs without a tape measure

This is a trick I saw on an episode of #thisoldhouse years ago that I use all the time. It’s nothing new, but it’s still very useful. Instead of measuring the location of the hole based on an assumption of how the panel will sit eventually, put the panel in its final place left-to-right and up-and-down, and transfer the marks directly to the panel. This works for drywall, plywood, OSB, you name it.