Have you been on your feet a lot? Perhaps you hoofed it around town to take advantage of the holiday sales? Maybe you stood in the kitchen a long time preparing a holiday feast? You might have been one of the strong ones who spent time volunteering or worked in retail or at restaurants for hours on end.
When you get the chance to finally sit down, try rolling your achy feet over a tennis ball. You can also do this little stretching exercise while standing up.
At first I was skeptical that something so simple (and free or cheap) would make much of a difference, but it actually does. 🙂