This type of edging works especially well for women with more "frontage" than I have, since it holds the edge closed more firmly than the original crocheted edge. (Alas, even if I gained 50 lbs, none of it would end up on my bust!) Here's how the edge looks when the buttonhole is open.
And here it is closed.
To make: When you arrive at the end of the BO for the front edge, do not break the yarn, but instead, use it to CO 3 sts by backward loop method onto a dpn of same size as you used for the edge (a 5.5mm in my case). Turn the needle around so that the yarn is coming from the bottom stitch and poke the left hand end of the needle into the edge so that it picks up a loop of the bound-off edge. Then, with a second dpn, *k2, k2togtbl. Now the RH needle will become the LH needle. Poke the left hand end through the next loop of bound-off edge and repeat from*. When you arrive at the end, break the yarn and pull it through the last 3 sts. Weave the end into the I-cord to bury it. To make buttonholes, simply work a couple (or more, depending on your buttons) of I-cord rows unattached and skip the same number of loops of the bound-off edge.
Since Janie H. now has my old Perth Cardi, I've begun a new one in some deep burgundy Helen Hamann alpaca, after a disappointing experiment with SMC Select Highland Alpaca Fino. I feel guilty about not having loved the latter, but it was just too softly spun and wasn't doing the job for me. Here's the new cardi so far:
Such a useful colour!
Finally, I've engaged in a little rule breaking. I bought a couple of skeins of Koigu last fall in Toronto and they've been sitting around waiting to become a scarf. I love Veronik Avery's Ribbon Scarf from Knitty and wanted to do something similar, but maybe just a little less open. Here's my experiment with fern stitch; I used double YOs instead of singles and I PRESSED DOWN WITH THE IRON. Yes, that's right, I laid the steam iron down hard to create a thin, flattened effect.