I extracted 6 x jade colour strips from my existing Moda Sweet jelly rolls. I have two, so that gave me 12 strips each 2 1/2" wide. I pieced each strip with a 2 1/2" strip of calico. Then I cut each set of strips into 2 1/2" wide rectangles. Then I matched each rectangle with an upended partner to give me a square checkerboard block made up of 4 x 2 1/2" squares.
I laid them out as 8 blocks x 12 blocks and because my colours were limited, I opted for a patterned repeat rather than random mixing. That's where lesson 2 comes in. I really think an odd number would have given me a better size. Perhaps 9 blocks across x 11 blocks deep would have given me a squarer top rather than rectangle. So I should have tried a few more ways before I started stitching and of course, the size ends up completely different once stitched than when it was laid out on the floor!
I've almost finished piecing the blocks and will add to the sides with left over calico to square it up and maybe the top.
Lesson 3. It will still be gorgeous even if it's not exactly right and the next one will be even better!