Option one has you make an I-cord first and then pick up the stitches along it. It can be used either when your I-cord is done in a contrasting colour or the same as the rest of your knitting.
In option two the I-cord and the cast on base are created together, simultaneously. You'll increase into the front and back of the first I-cord stitch while making the I-cord as per usual. Once completed, the I-cord will have a row of live stitches along its side, ready to be knitted. The only issue with this option is that the live stitches are the same colour as the I-cord and because these live stitches turn into the first row of the yoke the transition between the I-cord and the rest of the body messes up.
And here's how to do it:
Option 1 - use for a contrasting I-cord or the same colour I-cord
Option 2 - use for main colour I-cord only
I'm working my I-cord over 4 stitches here.