*Cut two squares of fabric any size
*Place one fabric (green in the photo) face up on your work surface. Position the fabric (orange in photo) 1/4" below the first fabric, right sides together.
*Sew a scant 1/4" seam, aligned to the top (orange) fabric edge.
*With a hot iron and a spritz of spray starch, press the piece OPEN with the seam allowances toward the top fabric. In the model, that would mean that the green seam allowance would be covering the orange seam allowance entirely.
*Fold the top seam allowance over the bottom seam allowance and press with another spritz of spray starch.
*Lastly, with a hem stitch foot (Bernina #5 or 10) and the needle position over two clicks to the left, top stitch the hem in place. The above photo shows the official "back" of the piece with both lines of stitching showing. I like this side best.
*Keep in mind when you design a piece with Pojagi seams, that one seam allowance (the bottom fabric) is 1/2", while the other seam allowance is 1/4". This can make a big difference over the course of a project, and you have to plan accordingly. If you don't alternate which piece you position as the bottom or top, you can come up with a final shape that is not the desired size... or you can just "wing it" and trim the pieces to fit...