Most books want you to sew the square first then cut them into triangles. They say it is more accurate. I am not sure if it is or not. I cut the triangles out and then sew them. You have to be right on when you cut if you do this. You have a better chance of being off this way. It requires you to draw a line threw to sew from if you sew it in the square so you get a staright seam where it is supposed to be. Hope this helps. It is personal preferance.