Once you've chosen a pattern, I recommend transferring it onto regular weight paper to work with. It's easier if you plan out your stripes in advance - consider their width and spacing. The placement of the stripes (but not the color order) is mirror-image on the front pieces, and back pieces respectively. I use 3/8" and 5/8" satin ribbon, though it's my belief all the ribbons are 5/8" width, and the narrow ones are simply the wide ribbons folded over because they only have one selvege.
When placing your stripes, I recommend gluing them down before stitching. They'll be straighter and won't shift around as you sew. You'll need to match your thread to your ribbon color. I find it easier to position all the ribbons, then sew them all on by color (so you aren't rethreading the machine & bobbin so much).
