I made a large one last fall, and I loved the process! If you sew the center star together in two separate sections (half and half) and then join in the center it goes together much flatter. If you try to join the sections in a circle, you can end up with a pucker in the middle. If it's a little puckered you can sew a little deeper on some of the seams (across the star from each other) and it will solve the issue. I also did the strip sets method, which is tons easier than cutting a gillion little diamonds.
Here's mine
http://www.quiltingboard.com/t-79225-1.htm