I used this to make a didymos style sling, and we LOVE it!!
http://www.nandu.hu/English/Practical/babycarrier.htm
I made one significant change though, I cut the strips on the bias, so I got the benefit of the bias stretch and give. I took 3.25yds and cut it to make 3 bias strips 26 inches wide, then pieced them together. It is very comfy in the cross front carry with my 11 month old.
Oh, i used thin cotton batik.