Okay, maybe life-saver is a bit much. What I'm talking about is a yarn ball winder. I bought one several years ago when I attempted to learn how to do regular knitting, which as I've said, didn't work out too well for me. Anyway, this is a purchase that I look at time and again and think how glad I am that I have it. When I buy yarn. the first thing I do is wind it on the yarn winder to get it into a nice ball that is workable and convenient in size. You may get 2 1/2 balls of yarn from, say a Red Heart brand of solid colored regular size skein of yarn. My yarn winder is a Royal brand. It mounts onto a table top and tightens with a wing-nut screw underneath. I put mine on a piece of wood in the back yard from my daughter's climbing toy we took down over a year ago. I stapled a plastic place mat to it to prevent the yarn from getting dirty and getting scratched by the wood. Plus, it makes it portable which is nice when you want to sit in front of the TV and mindlessly wind yarn---it's fun!
You can see how nice it winds the yarn into a workable size ball. I bought mine in a specialty yarn store and really that's the only type of store I've seen them. You generally wouldn't see ones, I don't believe, in a Jo-Ann or Hobby Lobby store. It would be great if you did then you can use your handy dandy 40% off coupon! At the time, I paid about $34 which I thought was pretty high for about 6-7 years ago, Even now, it seems expensive. It is so worth your money and time though. You'll be glad you got one. Now, there are electric yarn winders. I saw one reviewed on YouTube and was so NOT impressed. Trust me, get a manual one. An electric one does not make it easier. I've only seen one brand of these so you probably know which one I'm talking about. Check with your local yarn specialty store. Be prepared to spend a little, but you'll thank yourself time and again.