I make skirts all the time and rolled hems, the last step in most skirts, is the one I dread most (I might buy a serger for this very purpose). I've never had any luck with the rolled hem foot. Even my sewing teacher--who learned to sew when she was 7 years old and is 67 now--said "a person just has to be a savant to use the rolled hem foot correctly." She uses her serger for rolled hems. Since I don't have a serger, she taught me a relatively easy way to do rolled hems with a regular foot and a straight stitch. The
second approach on this blogpage is exactly what my teacher taught me and what I've been doing; however, you might be more interested in the first technique, which utilizes the rolled hem foot:
http://blog.megannielsen.com/2013/05...-a-rolled-hem/
Good luck and let us know how it goes!