I am knitting a sweater from the neck down. It is a one piece cardigan on a circular needle. I'm now at the point where the instructions tell me to knit across the front, slip the sleeve stitches onto a stitch holder, cast on 14 more stitches, then knit across the back to the next sleeve, slip stitches onto a stitch holder, cast on 14 stitches, and knit across the other side of the front. What is the best way to cast on stitches in the middle of a piece? I only know one way to cast on and I don't think it will work here.