Best thing I have found is have at least 3 pairs of boots, all different.  Wear a different pair each day,  seems every shoe puts stress on parts of the body differently.  By moving those points around it greatly helped.

I also agree lowering sugar can help, but not for everyone.  Arch supports can really help to, check to see if your insurance covers it, I've had arch supports since I was really young.  I can usually get by without them now buying good fitting boots and cycling through them.