Some yarns are absolutely gorgeous to look at but can feel a bit harsh to the touch.
This is often the case with yarns that are spun in a more traditional way or where the fibres are shorter and need to be protected in the spinning process.
Spinning and dyeing processes that rely solely on natural dyes and that don't use chemical softeners can also result in yarn that feels harsher than what one might expect.
The good news is that many traditional yarns will soften simply through using and wearing them. But rather than putting up with scratchy yarn, you should give your finished project a gentle bath in quality wool wash.
Some knitters use a gentle shampoo with a small dose of conditioner. You will be amazed what a difference this will make!
Take care not to use harsh detergents or water that is too hot - you want to soften the yarn without making it loose its colour or accidentally felting the yarn.
It is usually advisable to wash the finished project rather than the yarn - first of all, it is a lot easier to do, but some yarns, especially those that are spun on a waxed cone also benefit from having that extra bit of protection while knitting or crocheting. In fact, machine knitters sometimes add wax to the yarn they use to make it easier to knit with them!