think of each row as a separate entity... you will have one row that is 2" corner block, 10" x 2" sashing, 2" corner block.....etc....
the next row will be 2 x 10 upright sashing, 10" block, 2 x 10 upright sashing, etc.... now you just have to sew the rows together... if this quilt is on point... then that's a whole different thing...