DIY Hanging vegetable sacks?

I saw these Orka hanging vegetable keep sacks and as I can't buy them (availability and the price are the issue) I was wondering if anyone has an idea or advice on how to make them yourself?

http://www.thegreenhead.com/2011/08/vegetable-keep-sacks.php

All you'd need to do is sew a tube with a drawstring on both ends, sew a dart near the exit end, and attach a loop for hanging. :)