To wind a centre-pull ball of yarn by hand:
1. First, unwind a skein (hank) of yarn using either a swift, or just by draping the skein over my knees, and gradually unwinding it and dropping it loosely onto the floor, or into a paper bag or box, so that it forms a loose pile of yarn spaghetti. If you have pets or children, I think the best thing to do is to drop it into a bag or box, so the critters can’t tangle it up.
3. Continue winding until you have a little ball on your fingers, and then take your fingers out, and put your thumb into the centre hole, and then continue to wrap the yarn, turning the ball every so often to wrap at a new angle.
For most types of yarn, it works to pull from the centre of this type of ball, and this also allows for 2 strands of yarn to be held together from the same ball, or for 2 pieces of knitting to be worked from a single ball (for example, when knitting 2 pairs of socks at the same time from a single ball).
However, some delicate or ‘sticky’ yarns, such as mohair or lace-weight silk yarn can be difficult to pull from the centre, as their strands tend to stick together and tangle. In these cases, it is best to knit from the outside of the ball.
Enjoy your lovely hand-wound balls!