B.K.S. Iyengar would describe the feet by saying, "in standing poses imagine that your feet are like roots growing into the ground."
Did you know that our toes are supposed to always have a little space between each of them? Due to wearing shoes, we end up with deviated toes, curved Achilles, collapsed arches, and the list goes on. While some of these issues are related to how we formed in the womb, all of it can be helped by giving the feet a bit of focused attention. We want to try and find a balanced foot, so we can feel the arches lifting and gain equal weight on the outer edge, big toe, and heel.
The tendons that form on the anterior base of the ankle cross over all of our little joints and to the tip of our toes. These have a pretty distinct line. If you flex your foot gently, you can see the line, especially the one leading to the big toe. Shoes push our toes off to the side and these tendons can become curved and off-track.
This is one easy way to create space between your toes, getting the tendons back on track. Sit with a block under the ankle and knee (block under knee not in picture) so the knee and ankle can rest. Then, slide the tips of your fingers in between your toes. Sit like this for a few minutes, occasionally squeezing the toes into the fingers (creating movement). It's not shown here, but it's easier to do with the opposite hand to the opposite foot.
Now take your fingers away and extend your legs into dandasana. You'll see and feel the difference in your feet. It's quite amazing.
Your feet are so important in Yoga. They are the power source at our base that sends the vitality up into the body. They awaken all of our cells and remind us to breathe. They help us expand in all directions. Whether they are facing the sky in inversions or growing roots in tadasana, they are our connection to the earth. Marinate on that!