I created this yarn cozy because I was tired of how floppy and loose my sock yarn balls would become half way through my sock knitting after rolling around in my knitbag. This mesh ball cozy will shrink with the ball, and keep it quite tidy.

Thread a bit of waste yarn or i-cord through the holes at the top to create a draw-string. Pull it tight and tie it in a bow for extra security. This drawstring can be reused over and over if it is long enough.