I'm using the bottoms of custom built bookcases. These are enclosed with doors to hide my magazines and quilt books. I added a 4 x 8 x 5.8" piece of plywood to the top and then a small trim piece around the edge to hide the edge of the plywood. Added brackets about halfway down between the 2 bookcases to add another piece of plywood to house my smaller totes of scraps, fat quarters and pre-cuts. I purchased a self-healing cutting mat, one side is green and the other side is black, both with markings for the top. The top photo shows the newest cutting mat. The other photos were before I changed out mats. You can also see the changes I made in my fabric shelves as well as the big board on my ironing board. Bottom 2 photos were when I had just moved in and was still figuring out how to arrange things. The top photo is how it is now.