Here's the supply list:
Foam board for backing (choose black in case the board peeps through a bit)
Stain (if you want)
Framing pieces (I used 1x3s, you can use molding too for a more finished look)
Paint for framing pieces
Jute and staple gun for hanging
So, at first, I didn't cut the shims down and the herringbone pattern was just too large and you could only really see one line of the pattern, so I decided to cut the shims down. The easiest way to cut them in half is to cut them in the packaging.
Next, I drew a line down the middle of the foam board.
I then painted the frame, but I suggest you do this beforehand :) Just in case you get paint on your shims.
Next, I got my hot glue and some ribbon and glued the ribbon along the edge to make the finishing touch. Then you don't have to worry about foam board meets shims meets frame ugliness :) It will all be hidden behind the ribbon.