This is how I knit socks ! I always knit 2 socks together, with 2 circular needles, and of course  2 balls of wool ! (I even knit 2 pair of socks together : it means 4 socks on my needles !)

Why together ? Because I prefer to have 2 socks exactly the same !!!

When I come to the heel, it becomes very complicated.

And when I knit with 2 or even 3 yarns, it’s even more complicated and I keep every balls of wool in a bag for the sock 1 and in another bag for the sock 2.