The feet have to endure a lot each day. They carry all of your body weight around and are often neglected unless they develop a painful problem. If you are training in martial arts, or simply wish your soles weren't so sensitive, you can begin toughening your foot soles right away. It will not happen overnight. It will take some time, but with daily practice eventually you'll develop tough feet that can withstand a great deal.
Walk barefoot as much as you can around your house and yard. Walking on carpet, wood and grass without foot protection may not seem like much, but will start to condition your feet to be less sensitive.
Run or walk barefoot in sand once a day, if you are close enough to a beach or other sandy area to do so. Particles of sand are abrasive. The soles of the feet will eventually develop calluses to protect against the abrasion.
Walk on concrete, stones and gravel around the city whenever you can. Exposing the soles to various textures will harden them up. Your feet may feel sore at first, but eventually with practice you will be able to walk on almost any surface without pain.
Use a leather strap or a conditioning board used by martial artists for iron body training. Iron body conditioning is a method of toughening and desensitising parts of the body for martial arts. You can purchase these items from martial arts stores, or use a leather belt or a stick to tap the bottoms of your feet.
Walking barefoot will leave your feet more susceptible to cuts and scrapes. Treat wounds on the feet as soon as possible to avoid infection. Avoid walking barefoot until the wound has healed.