I learned these fantastic foot exercises from Jenny Otto.  They have been invaluable to me, as I do most of my commuting and errands via foot.  These exercises are great for finding more flexibility in your feet, increasing circulation, and creating greater stability. The feet are your connection to the earth and the foundation of your entire body. Keeping the feet open and aligned can alleviate or prevent problems in your ankles, knees, hips, and low back.

1. Massage the sole of your foot with your thumbs, giving extra attention to anywhere that is particularly tight or sore.
2. Insert your fingers of your opposite hand between your toes, working the fingers down as far as you can towards the webbing of fingers/toes.
3. Circle your foot several times in one direction, then the opposite. Use the strength of your arm to flex your foot towards your shin to stretch your calf, then to pull the foot away from the shin and stretch the front of your ankle.
4. Spread your fingers wide to stretch between your toes; hold for several seconds, then remove your fingers.
5. Twist, then pull each toe. I twist twice to the left, twice to the right, then pull. You may hear some pops; that’s ok.
6. With thumb & forefinger, take hold of the base of your big toe and the base of your little toe. Move in opposite directions to open your transverse arch.
7. Make a fist, pound out the bottom of your foot.
8. “Clap it out”, clapping your hands with your foot between them.
9. Take hold of ankle, shake your foot out without using any of the muscles in your leg or foot.

For passive footwork, try YogaToes; they give me a lot of relief when my feet are bothering me.

Do these exercises as often as you can. You have 26 bones in each foot, along with small muscles, tendons, and ligaments. More flexibility and space in your feet is always a good thing.