I made it at TechShop. www.techshop.ws
Step 1: Cut pieces for shelf
I started with a 1 x 12 piece of pine board. I first cut the board to 16" long. Then ripped the board along the length to create a 4" wide section and a 6" wide section. (These dimensions aren't exact as the saw blade removes some of the material, but you get the point.)
From here I cut the end of the 4" wide board twice at a 45 degree angle. these two triangular pieces will be the support for the shelf.
No you have your pieces for the shelf! Feel free to cut the large and smaller piece to whatever shape you please. I simply rounded the corners where the shelf will be exposed.