For this bag you will need:
Approximately a ball and a half (150g) of Double Knit (I used Ice Yarn - Magic Light 22036)
4mm crochet hook
A darning needle
A Button
This pattern uses UK crochet terms.
Stitches used: Chain (Ch), Half Trebles (HTr), Double Crochet (DC), Treble Crochet (Tr), Back Post Trebles (BPTr) and Front Post Trebles (FPTr) I have added photos for these post stitches in case you are not sure how to do them.