NEED FOR CUSHION!
Most shoes aren't always what is bad, usually it's the crummy insoles they come with! there are many possibe reasons that you may have callouses on the foot, but try cushioning arch supports like spenco polysorb cross-trainers(http://www.
Spenco.Com/products/footcare/poly-sorb). If these don't help, see a podiatrist.... Routine trimming or surgery may help too, depending on a accurate diagnosis.