I needed a way to carry my mobile phone for those times when I had no pockets or bag. My daughter was also constantly mislaying her phone, so I came up with this phone cosy. My 2nd daughter also uses this to carry money at discos.
Double drawstring top so phone/money is kept safely inside. Hope you find this as useful as I have.
Gauge is not very important as the cable ribbing is very stretchy and you work until length required.
The drawstring is made using a small crochet hook and a single chain stitch. This gives a strong thin cord, that is constructed very quickly. Alternatively you could knit a cord. Yarn is held double throughout to get a 4 ply weight.