You’re putting an I-cord edge on a blanket, shawl, or a potholder, and whoa: you are approaching a corner. You need to ease your I-cord around that corner so it won’t be too tight.
Work applied I-cord until you get to the end of the edge of the piece.
Work 2 rounds of I-cord without knitting the last stitch together with a stitch on the edge.
To do this, simply work all stitches (typically 3 or 4 stitches for an edging I-cord), without knitting the last stitch together with a stitch from the edge of the knitted piece. Transfer (or slide) the just-worked stitches so that they are on the left needle again, and work a second round of unattached I-cord.
Now, pick up a stitch in the corner of the piece and work 1 round of attached I-cord by knitting the last stitch of the I-cord round together with the picked-up stitch.
Work 2 more rounds of I-cord without knitting the last stitch together with a stitch on the edge.
Alternatively, simply work 2 or 3 rounds of unattached I-cord at the corner. (Any more rounds of unattached I-cord, and a visible hole will form.)
Now resume working applied I-cord on the next edge, as worked on the previous edge.
See how neat it looks? In the photo above, you can see the space between the last stitch on one edge, the center stitch, and the first stitch of the next edge.
Hint: work an extra round of I-cord, without attaching it, whenever your applied I-cord edging seems too tight.