In the cold season of winter, many of us are breaking out our sweaters daily, and at some point will face the colder reality that, no matter how well-made, all wool sweaters pill. This is true whether you have one of those cheap merinos from a mass-market retailer or a hardier Scottish piece from a specialty boutique. With enough wear, all wool sweaters will pill over time. The question is just how much and how easily.
There are many techniques recommended online for how to take care of pilling, but beware: some of them will cause more harm than good.
To understand why, you have to understand how pilling occurs in the first place.
Wool yarns are made from intertwining animal hair fibers that have been carded and then spun. The areas where each fiber connects to another is weak, at least compared to the rest of the yarn, and can break with enough stretching or friction. When it does, the tiny fibers tangle into each other and result in the fuzz balls we refer to as pilling.
Cheap yarns are made from shorter fibers, so they have more areas for potential breakage and thus pill easily. Nicer, more expensive yarns, on the other hand, are made from longer fibers, but this doesn't mean they'll never pill. They'll just do so to a lesser extent and at a slower rate.
Once you have pills, you'll want to get rid of them, but be careful of the technique you use. If you pull the little fuzz balls off with your fingers, your sweater will look nicer and tidier in the short term, but you can create new breakages as you pull and thus create more pilling in the future. "Sweater stones," which are essentially like pumice stones for you knitwear, can do the same thing.
Instead of pulling the little fuzz balls off, try cutting. There are a number of sweater shavers on the market designed for this. Cheap ones on eBay typically don't work that well, but for $15 or $20, you can get a perfectly serviceable machine at any major department store. These will achieve what you want: to remove pills without creating any new breakages.
Of course, the other approach is to just embrace the pilling. With enough of it, maybe you can say you have a Shaggy Dog.