This is an easy pattern to knit a hat in the round, involving a pretty wavy cable which forms lovely waves before the decreases for the crown. It is a very warm yet stretchy hat and so will fit teens and adults. You will only need 50g of yarn, 4mm needles (circular or DPNs) and a cable needle. The hat is seamless so the only sewing required is darning in the ends - simple! It's also a small and quick project if you are new to either cables or working in the round.