I made a rag quilt for my DGD and cut 5" squares. I did sew the X on each square. To me it keeps your fabric from slipping and also it keeps its shape after washing and drying. I am cutting another for my DGS but making 8" squares and I am still sewing the X. I did not put any batting in either and it is just fine. If you want the quilt a little "warmer" use batting. Good luck.