The shelf in question is the $36 Gingham Triangle Corner Crystal Shelf Display from J Drew's website. A larger version is also available, or if you're feeling quirky, scoop up the Honeycomb Shaped ...

For a corner shelf, you’ll need to cut your shelf board to make a 45/45/90-degree triangle. To check that your shelf is level, place it on top of your nailing strips, and use your level on the ...