http://www.quiltingboard.com/posts/list/28714.page
this is the one i posted. the method relies on the top layer being equal in width to the bottom layer. that's all you have to remember. how many strips you have in each layer is entirely up to you. anywhere from 1 to 4 is the norm. the key is to have the center seam run from point to point diagonally. on one side of the seam you can even have the stripes going sideways.
if you search tube piecing, you'll get advice, links and pics. have fun! :-)