This is the second sock featured in the Claire Ellen Sock Club. The Fraternal Pairs Fili (teal) & Kili (lime) are actually 2 complementary patterns, both written for right & left foot. As the SKA challenge in October is Fraternal pairs, you can "choose your own adventure" with these.
The Fili sock features twisted knits and purls as well as cables without rest rows. For those reasons, I'm listing it as an intermediate sock. Not terribly complex, but not a walk in the park either. It'd be helpful if you've knit both cables and socks before.
The yarns used in the pictures are both Pediboo, which is a little thicker than the average sock yarn. No matter this sock can be knit with a finer yarn just as easily. Pick a yarn and needle combo that give you a fabric you like & the gauge listed. I used one skein per sock, so if you're working with a single skein, I'd recommend finding one between 380-400 yards.