I almost always double fold my fabrics, so I use the June Tailor Shape Cut for most of my cutting (as long as the pieces are in 1/2" increments), or I use my 12-1/2" square. I found that I made too many mistakes cutting the full WOF because of my short arms (I am only 4'11" tall).
The best thing my DH ever did was step on my 8-1/2" x 24" ruler. He felt so guilty that he gave me the money to replace it, and I bought the 12" x 18" Shape Cut. Then my son cut the broken ends off, so I got two shorter rulers (7-1/2" and 14").