Casting on for 2 socks on 1 Circular Needle
A Visual Guide

Step
1: Cast on half the required amount of stitches for the first sock. In this
case, 32.

Step
2: Starting from the same end of the needle and from a second ball of yarn, cast
on all the stitches for the second sock. There are now 32 stitches for the first
sock and 64 stitches for the second sock in my example.

Step
3: In the middle of the cast on stitches for the second sock, pull out a loop of
the needle cable and match up the needle ends. Notice how it appears that the
ends of the yarn that go to the ball are opposite each other.

Step
4: Hold the two needle ends close together. Begin casting on the remaining
stitches for the first sock, using the first ball of yarn.

Casting on complete. There are 64 stitches for each sock and the ends of
the yarn that go back to the ball are on the same half of the folded needle.
Make sure your stitches aren't twisted and begin
knitting!