Purpose of this stretch: While this is a great stretch for releasing tension in my hip flexors (especially my psoas muscle), I love pressing the heel of my straight leg back to stretch one arch of my foot at a time. This is a great stretch to get the calves warmed up before Down Dog (which is the next stretch I do).
Starting in a plank position with the shoulders over the wrists, step your left foot forward to the outside of your left hand.
Hold for five breaths, actively pressing the right heel back.
Step the left foot back and repeat with the right knee bent for another five breaths.