Standing poses are a wonderful way to build strength and stability, improve balance and proprioception (the ability to sense position, motion and equilibrium) in the body and mind. We practice yoga in bare feet to be able to use and build agility of the feet and ankles, and to ground from the lower body while integrating the engagement of the core and upper body. Agility in the foundation of the body and feet translates to more freedom in the ribcage and the spine.
There are several cues related to the lower body that can be applied to most standing poses: root the big toe mounds down and lift the arches of the feet, reach the inner heels downward and lift the pelvic floor, lengthen the tailbone down and draw the navel to the spine, engage the quadriceps and draw the kneecaps up. These pairs of opposites keep us safe by teaching us to tune in to the dynamics of the actions within the alignment. This is yet another gateway to bringing awareness to the body and looking within.
Enjoy your practice. Namaste!