What should you look for to make sure your feet are healthy? Here are some general guidelines:

Balance. A good test for balance involves standing on one foot, with your arms out to the side and your eyes closed. If you are less than 30 years old, you should be able to balance for 15 seconds, 30 to 40 years old for 12 seconds, 40 to 50 years old for 10 seconds and over 50 years old for seven seconds. This can be improved with exercises.
Circulation. Look at the color of your toes. Do they look like a normal nail color or are they leaning towards red, white, purple, or blue? Press down on the nail of your big toe until the color blanches. Now let go and allow the blood flow to return to your toe. The return of normal color should take 2 to 5 seconds in a person with average circulation.

Flexibility. How flexible are your toes? Try to pick up a marble or a small dish towel with your toes. To test your ankle flexibility, hang your heel off of a stair. Now let the heel go below the level of the stair. If this causes pain, stop the test. If your heel goes below the level of the stair without causing strain in your calf, that is a good sign. If there is some strain, this can be improved with flexibility exercises.

Pain. A healthy foot does not produce any pain.

Sensation. Take a pencil eraser and lightly run it on the top, bottom, and both sides of your feet. The sensation should feel equal in all quadrants. It may tickle on the bottom of the feet. That is normal.

Skin. Check your skin for calluses, blisters, or areas of irritation. Stand next to your shoes. Are they shaped like your feet or are they causing areas of constriction that may result in irritation? Put your hand inside your shoe. Are there seams, tacks, or rough places in the shoe that correspond to calluses or blisters on your feet?