This tutorial of how to make cozy slippers from an old sweater is an excellent way to repurpose a clothing item into a warmth for your feet.
Before you donate an old sweater, look at it once more and see if you can picture it being made into something else you may need.

Maybe a cozy pair of slippers ?

Hopefully I can help you to see things you may find cheaply at a yard sale for not just what they are but what they could become with a little creativity.

If yes, click here to read this article:

http://www.instructables.com/id/Cosy-slippers-from-your-old-woolly-jumper/