nativetexan

i cut some ugly thin white fabric into 10 inch sqs and then laid a strip right side up diagonally down the square. laid a strip face down onto that one and sewed to that one, flipped and pressed. then sewed another to that one and filled one side to the corner. then turned the block and stitched more strips to the other side until filled.
then pressed each block and laid ruler on the back side and trimmed to 9 1/2 inches. just watch your corners. make sure you have fabric in the seam allowances.
fast and easy.