In answer to Alison's questions (thanks for making me feel smart)....
I hold the yarn over my right index finger so I'm not going to be much help there. Somehow the idea of switching the yarn to the other side makes me feel out of whack though I am interested in this technique called combined knitting. You can see the technique for combined knitting
here. It just looks like it could be super fast. Still the idea of changing my knitting technique is a little scary. Just ask my friend Molly who two years into her knitting life accepted the fact that she was producing a twisted stockinette stitch and had to change how she was knitting. Poor Molly.
To keep edges from rolling you need to incoporate knit and purl stitches into the edge by using rows of purl stitches, ribbing, or some other pattern on the edge that has knit and purl stitches OR you can knit a little extra at the beggining to be used as a hem that you would fold under and stitch in place in the end.