“I Always Pick The Thimble” has a great sewing tutorial for how to make a yarn ball. Here’s how they describe it:
“Here’s a simple way to make your own center-pull yarn ball if you don’t have a ball winder. It’s a great way to wind yarn that may have been purchased in a hank or wind yarn that has been pulled out to start over on a project. Either way, it’s an inexpensive alternative to a ball winder.”