i think the newer methods described in this thread are much easier...the templates, pre-cut with accu-cut and also the quiltsmart as well as variations which are paper pieced...alll wonderful. I do think an accurate seam allowance is the key. it's a good idea to make up a "block" and stitch to see if your "rings" or arcs are fitting the "football/melon" shapes. if so then keep going. I think it is more time consuming than sewing blocks of squares and triangles for sure, but it is also very rewarding when it comes out well. there are many beautiful pics on this topic!! you go girls!