I use 2 circular needles and knit both socks at the same time. There's a great book out called "Knitting Circles Around Socks" by Antje Gillingham that shows you step by step how to cast on and set up to knit both socks. Her second book "Knitting More Circles Around Socks" shows both cuff down and toe up methods. Once I made a couple of pairs of socks, I learned the toe up method and love it as you keep knitting until you run out of yarn. No left over balls!