Fall and winter are when I pull out the knee socks!! I remember thinking several years ago "where on earth do the Bob Jones students get their long socks?". Thankfully, I have found several places that sell knee socks since then!!
I have been amazed at how "put together" I feel just wearing a pair of these socks instead of my normal "gym socks" (which is what I've always worn.). You can buy fun styles or more dressy styles. You can layer under them for extra warmth but but try them without all the extra sock layers and see how warm they keep you!
Our present house gets' rather chilly in the winter. The main floor is not insulated and you can literally feel the cold radiating up from the "basement". By wearing these socks, I have kept myself much warmer than I would have otherwise been. I am amazed at how warm they keep as opposed to the "gym socks" that I wear during the summer!
You can find Knee socks without much problem. My favorite place is Dillard's, where you can find solids, stripes, prints, and polka dots without much problem! TJ Maxx is another place, but they don't seem to have a very good selection at the store I visit.