Most big box yarn is sold in a center pull ball. This allows you to pull your working yarn from the middle of the ball, instead of the outside. Knitting from a center pull ball keeps your yarn from rolling everywhere as you work. But sometimes the yarn gets loose, or you buy a hank that needs to be wound. Usually you would use a ball winder with a swift to create one of these, but they can be expensive.
This tutorial will show you how to wind one yourself.
Step 1: Make a slip knot and attach it to a size 50 needle or other large tube (paper towel roll, curling iron, permanent marker).
Step 2: Wrap your yarn around the needle and hold the tail of the yarn from the slip knot.
Step 3: Turn the needle and wrap your yarn around the needle. I turn it about a third of the way each time.
NOTE: As you turn, wind the yarn at roughly the same point for each turn.
TIP: If you want the ball to be taller, wind the yarn slightly above the top for a few rounds.
Continue winding until all of the yarn is wound, then slip the tail under another strand on the outside of the ball