Cut a strip of fabric 3'' by 46''. Then fold it over, with the fold on the left side.
If you're using lining fabric like I am, anything that's shiny or flimsy that may fray easily you need to seal all ends of the fabric. Simple light a candle and hold the fabric high enough above the flame so that it starts to melt but not burn. Move quickly so the smoke doesn't discolor the fabric. This actually gives a nice curl look to what will be the rose petals too.
Then using your rotary cutter, cut scallops along the top edge. (I think this is where I went wrong, I think if I had folded the fabric over on it's self a few more times and THEN cut scallops it would have turned out more rose like.)
Open up the entire length and on ONE END ONLY cut it into a narrow end, just like the picture below. This is the end where you'll start rolling up your fabric to form the rose, but not yet.