To prepare your ruffles, fold the 3" strips in half(long length) and press.Run a gathering stitch along the raw edge with your machine to draw up the fabric to make your ruffles. I like to use my basting stitch on my sewing machine for this, but if you don't have that option, set your machine to a straight stitch and then set it on the longest stitch length your machine will go to.
Cut the back fabric out if you can see the print showing through to the front side.If it doesn't show, you don't neccesarily need to do this.
Stay stich your ruffles at the hem and neck edge to keep them in place.
Now your ready to finish sewing your dress following the directions your pattern gives you.