Stand on a rolled up yoga mat with one foot in front of the other. Alternate shifting your weight from the back foot to the front foot. To advance the exercise you ca try 1) crossing your arms in front of your chest or 2) standing on one leg. Focus on your balance as well as the role your toes are playing in the process. Try not to 1) lift your toes off of the mat or 2) scrunch your toes up. If you are in doubt please seek the advice of an appropriate exercise professional.