2-3 Wool socks.
It depends on how big of a hat you want. I use one sock,"body", if you will, for the grey/white part of the hat. The white hat took about 2 and a half socks for the red and black,"rim". The solid red rim has the red parts of two cut in half and turned sideways. Good Choppers.
No, your teeth don't quite cut it. (hehe, "cut it") Socks are thick. Thread/Needle
Use your own discretion on the color, heck use a friends discretion too! You will want the colors to blend. More than one color might be needed. Also, needles are a must. Twigs don't work. A good work area.
Don't be a slob like me. Use a table or something.