I have a ruler that is perfect for centering the 5 in square in the middle of the 10 in square. It's called Spare Change ruler. I got it at Missouri Star Quilt Company. I made the quilt top in this video in Sat afternoon. It's my DH favorite quilt. He keeps it on his chair. Now my Son in Law, Uncle and nephew want one like it. I used the Kansas Troubles layer cake and charm pack.
http://www.youtube.com/watch?v=gyZu-j720nw
I don't try to save fabric when making a quilt, waste is just normal for a fun fast quilt to make.