Start with two 6" squares.
Place the squares right sides together and stitch a 1/4" seam down each side.
Cut through both layers 2" from the edge. The cut is parallel to the seam you just made. Cut 2" from the other seamed edge.
You now have two seamed portions and two loose strips.
Press the two seamed portions open.
Add a strip to each one to make two rail fence blocks.
.Place these two blocks right sides together and match the seams carefully at the end
Stitch across the ends where you match the seams.
Cut again, two inches from the ends where you made the new seams.
You have made two nine-patch blocks!