I've been knitting an i-cord edge on my cardigan and I thought I'd share the way that I do this. I've searched online for several explanations of how to do an attached i-cord but this is the way that works for me. No need to pick up all those pesky stitches around the edge. Just start with a simple 3 stitch cast on.
For the sake of this tutorial, I'm using a different color yarn. To make an attached i-cord you need 2 double pointed needles.
WITHOUT TURNING YOUR WORK, knit those three stitches. Next, with your garment's wrong side facing you, pick up one stitch.
DO NOT TURN YOUR WORK! Slide your four stitches to the other point of your needle (as shown) keeping the yarn in back.
Knit the first two stitches and then knit the last two stitches together (this is including the one you picked up). You will now have three stitches again on your needle. You are now ready to pick up another stitch and repeat the process.
As you move along in your work, you will notice a nice cord forming around the edge of your garment. When you come to the end of your work, cut the yarn and thread the tail through the three stitches on your needle and pull tight.