Practice web, equipment question

This post is less about the art and more about the tools. I made an ugly cutting board a while ago and never sold it. When I needed a board to draw on I grabbed it and drilled some deep holes in the top edge for holding pens.

I keep saying I'm going to go in with a router and make a little divot in the upper right corner of the board for my eraser. But I haven't yet.

The question: do you have any fully custom gear you use? Something not available in stores or something that fills the place of something in stores that you just made yourself?