I learned from the back of a Wilton box of fondant! lol
there is a tutorial here on CC. i tried once, using that tutorial and wasn't able to make a succesful bow on my first try. for next time i will make the loops smaller, various sizes, and where the ends are twisted will be shorter. also, there is a website i just saw posted here yesterday called http://www.make-fabulous-cakes.com/index.html that also has a step by step guide.