This time I used the “tubular cast-on #1” from Vogue Knitting. It was a little tricker than the version I used for my first father-and-son socks to convert to in-the-round knitting, but it’s much stretchier.

Notes to self:
Single cast-on for half the required number, plus 1 (35). K1; (yo, k1) to end (69 st). Arrange sts in the round (for magic loop, 34+35).

To start 2nd row, sl 1 st from right needle to left; knit that st together with the first to join the round seamlessly (68 st). This counts as the first st of the round.
Rnd 2: (K1, sl1 yf) to end.
Rnd 3: (Sl1 yb, p1) to end.
Rnd 4: Rep rnd 2.
Rnd 5: Rep rnd 3.
Rnd 6: Begin normal k1, p1 ribbing.

I added reinforcement thread to the heel but forgot to do the first toe; that was just as well because I think I would have run out on the next heel if I had done so. (I could have bought more reinforcement thread, but I didn’t bother.)