It makes sense that if your feet feel painful, you should see a foot specialist. However, if you wait for pain to appear before seeing a specialist, sometimes you might wait too long. You should also be on the lookout for these other signs that something is wrong with your feet and may require treatment.
It's not unusual for your leg or foot to go numb temporarily if you sleep on it or sit on it funny. But if this is happening regularly, or if your foot is going numb for seemingly no reason at all, then you should definitely make a doctor's appointment. Numbness and tinging are often signs of nerve damage. This could be the first sign of a neurological condition like MS, or it could be a sign that one of your nerves is being compressed by an injured tendon or ligament.
Does the shape of your foot seem to be changing? Perhaps your big toe has started to look like it is popping off the edge of your foot. Maybe one of your toes seems to be curling up, or perhaps another toe has a large bump at one joint. These deformities could be the beginnings of bunions, hammertoe, or another similar condition. They may not be causing your pain right now, but if your foot doctor does not get you into a brace or orthotics to slow the progression soon, the pain will come.
Do you wake up and sometimes feel like you can barely bend your feet? Perhaps they have this generalized feeling of stiffness when you first start walking in the morning. This can be an early sign of arthritis. Sometimes the joints become stiff and seize up before you develop any actual pain. Nerve damage can also cause intermittent stiffness. It's best to let a doctor take a look at see what the most likely cause is.
Another worrisome sign is if your feet are often swollen. The swelling might be worst in the morning when you first get up, or it might be worst in the evening after you've been on your feet all day. This could be an issue with the structures in your feet, or it could be a disorder of the circulatory system, but either problem requires diagnosis and treatment.
Don't wait for pain to see a foot specialist. Seek care if you're dealing with any of the anomalies above.