I built a frame by attaching two stacks of 6 1x2 bricks onto a 2x6 base two plates thick. Next I added 2 stacks of transparent 1x2 bricks and toped it off with a 2x6 plate layer and finally a tile layer. I started an anchor layer of cheese slope pieces by attaching them to the 4 exposed studs and then filling in the rest of the pattern. The pairs of cheese slopes form squares and can be in any of four orientations depending on your pattern.
The piece holds surprisingly well considering there isn't much holding the cheese slope pieces in but should still be treated tenderly as 56 cheese slope pickup isn't very fun :)