This one is a phone sock I made for Tony because he was carrying his phone around in an actual sock, an old (clean) one. I made it in the pub, which caused excitement among the regulars.
It's just rows of double crochet, alternating every other row. It was approximately DK weight with a 4mm hook. I added a little button loop in chain stitch just to hold the phone in, as it's not a tight-fitting cover.