Success!
Okay, so I just frogged my Koigu sock a couple of rows and wore it, and it went up my, um, shapely calves just fine. Google to the rescue: a search for "stretchy cast off" made me realise with a relief that I was not the only one to have this problem with toe-up socks. So here’s what happened. I found this list of stretchy cast off techniques which mentioned a Russian cast off (scroll down to post # 4 by Spinerella). I tried it:
Basically, purl the first two stitches to be bound off together.
Then loosen the resultant purl stitch and put it back on the left needle. Then purl it together with the next stitch. Keep doing this till all stitches are cast off. Voila! All stitches have been cast off, with a neat, yet stretchy cast off. The edge looks loose and curvy but fits snugly over the leg.
And as you can see, it fits nicely and snugly, with no problems whatsoever. I am in love, and cannot wait to cast on for sock number two.
