I went to a yarn store that's going out of business and bought 1 skein each of cute sock yarn. Then I find out that it takes 2 skeins to make adult socks! What do you do with sock yarn other than socks?
The other thing you can do is to use 2 colors and make striped socks. Don't know if you're experienced in using different colors in knitting, but you just carry the unused one in the back (or inside in the case of socks), winding the unused color around the in-use color each row so you don't have holes. You could do 2 - 4 rows of each color for fine stripes, or 10 - 12 for broad stripes. I used to just toss half-skeins of yarn, but eventually discovered the use-one-color-for-the-brim-and-one-color-for-the-crown hat knitting!