Whenever possible, I like to eliminate waste and use as much organic, natural, recycled, renewable, etc. material as possible. I stopped using dryer sheets a number of years ago, and I originally switched to method’s fabric softener, which is super concentrated (so it only needs a little bit) and the container is refillable. But then I couldn’t find the refills, and I didn’t want to buy another bottle. I’ve seen the adorable hedgehog dryer balls, but I hated the idea of buying something plastic, especially when I had read about alternatives like using tennis balls or making your own dryer balls.
Of course, making my own almost always appeals to me. I used Lion Brand Fishermen’s Wool and these instructions from Instructables and got to winding. They get more felted over time, although mine do still look like balls of yarn, and I was able to get four balls about the size of a tennis ball out of one skein of yarn. One note: They make a fair amount of noise in the dryer, but that is a worthy trade-off to me.