I've been having a bit of fun with I-cord.
Applied I-cord is great when you want a neatly finished edge that looks good from both sides. After casting on 3 stitches provisionally, I work around the edge,
loading up my dpn with two extra stitches at a time (for a total of five),
attaching them one by one (getting down to four stitches here),
then back down to three stitches,
reload and repeat until back to the beginning, and finally weave the start and the end together (never a perfect match, but good enough).