Applying a finish to a door or flat project lying on a sawhorse can literally be a pain. So to ease the strain on my back and make it less tiring, I built an adjustable easel that holds the workpiece at a comfortable height, as you can see in the photo at this link.
This cutting board project could be built out of scrap wood already in your workshop. If you choose to use new stock from the lumber yard, both hardwoods and softwood are good choices.
Here is a big bookcase that you can build in a small shop. It comes apart into two pieces for easy moving.