I did some playing today: and built a box
I started with 2 Fat Quarters, and cut two long strips from each (4 inches wide, by the length of the longest side, about 22 inches)
I cut each strip in half, and then I arranged four pieces into a cross shape like this
I stitched parts 1 and 2 together, and then parts 3 and 4 together
and then I stitched the 1&2 unit to the 3&4 unit. I did the same with the second fabric, but actually had to re do the second fabric: as you can see below, the *correct* layout is to have one cross the mirror image of the other
I put the two crosses right sides together and stitched all round, leaving a small opening for turning. I snipped the corners off the obtuse / external angles, and snipped into the acute / internal angles so I could turn the whole piece right sides out. I used a chop stick to push the corners out, and then ironed it flat
I slip stitched the opening closed. To create the box, I needed to slipstitch side A to side B (starting in the internal corner), then stitch side C to side D and carry on with the final two pairs of sides, right sides together
In joining the edges, I slipstitched along the inner two folds, the right sides, (brown in this photo) but for another box I used a whip stitch, I dont think there is much between the two stitches for this.
This finishes to a box with a 5x5 base, about 4 inches high with a contrasting lining and no raw seams.