Check out the links below to learn simple recipes for making your own milk:
http://everydayoats.wordpress.com/2011/07/20/black-bean-milk/
http://www.nourishingmeals.com/2012/01/homemade-hemp-milk.html
http://www.seriouseats.com/2012/12/diy-how-to-make-rice-milk.html