Piecing some of my quilts can be a nightmare unless I plan ahead. I work with a pencil and a piece of graph paper, the graph paper keeps everything in scale. No ruler, I find it to be too intimidating.
First I draw the outer edges of the quilt. This keeps me from getting totally out of control size wise. Them I start drawn in the blocks where I think they should go. Usually I do this three of four times before I get it right. With Addie's quit, I knew I had 49 rather large blocks (Wisconsin went missing) fitting them into double bed quilt was going to be quite a challenge. The best way to fit them all in was to make them two different sizes.
Because the original fabric frayed a lot, I decided to sash every block with a 1/2" finished sash. This allowed me to zig zag every frayed edge to a cotton fabric to prevent further fraying. I'm mathly challenged so every block either finishes at 10" square or 8" x 10". This works well with the graph paper. I should also tell you that all of these 1/2" sashes were cut on the straight grain (parallel to the selvage for extra stability).