I prefer to knit my socks starting at the toe with a figure-eight cast on. Wendy demonstrates this and two other toe-up sock cast ons in an excellent article for Knitty. While Wendy uses double point needles (DNP) in this article, I prefer to use one circular needle instead. I tend to do a majority of my knitting on the bus and found that DPNs are easy to loose while traveling.
I was first introduced to knitting socks with one circular and the figure eight cast on in a class given by Sarah Hauschka at Hilltop Yarns. Sarah inspired Bev Glaeskas to document both techniques in a booklet called The Magic Loop. I found a website with good photos of the magic loop method. It really isn’t too difficult and helps saves money if you already have a circular needle. I’ve also used this technique for other projects.
One thing to keep in mind when doing the figure eight cast on is that the yarn tail will be on the opposite side of the beginning of the round.
Sarah mentioned in the class that she does a make one increase a little differently from the ones described in the Magic Loop booklet. Instead of picking up a stitch from the bar between stitches, she just makes a backwards loop around the needle. After the class I experimented with backward loop increases and drew pictures to remind me which way the loops should appear on the right hand needle for each side of the toe.