This tutorial will walk you through knitting on the cabled edge of my New Kid Cardigan. This is far from the only way to knit on and edge. I chose it because it works well with the garter stitch and cable used in this pattern. If you are using this method for a different project you might want to try knitting an edge onto your swatch to see if you like how the join looks before you begin.
Cast on the amount of stitches called for in the pattern and work across the row to the last stitch. Slip that stitch purl wise. This is the point where you will be joining your edge to the body of the cardigan.
Begin at the bottom left hand corner as you wear it. You will be attaching the edging at the end of every WS row, so open the cardigan so that the WS is facing you.
Then pick up a stitch through the bottom garter ridge as shown below.
Continue picking up stitches through two out of every three garter ridges until your edge has been worked around the neck and down to the other corner. If your row gauge is off from that called for in the pattern you might need to pick up slightly more or less often. It's fairly easy to tell which garter ridge you should be picking up through by eyeballing it. The idea is for the edging and the cardigan to be the same length. If in doubt lay your work flat after you have completed a WS and slipped the last stitch. You want to pick up a stitch through the garter ridge just next to the slipped stitch (the one that lays under the tip of the working needle).