Choose your fabric, cut two rectangles, sew a tube on top of both, pull ribbon/fabric through, knot, and sew sides.
I want this bag! DIY:
http://craftycpa.blogspot.com/2011/07/return-on-creativity-feed-sack.html
Simple book binding tutorial, I would love to try this:
http://www.tortagialla.com/2010/08/09/longstitch-bookbinding-tutorial-for-a-leather-journal/