Perfect your feet. A foot model gets hired because of attractive feet. Treat or remove blisters, broken nails, calluses, corns, scars and veins.
Get a professional photographer to shoot a portfolio. You won't make an impression by having an amateur take shots without the proper composition or lighting. Plus, a pro will give tips on how to pose like flexing your arch the right way.
Contact modeling agencies that represent foot models. Often, model agencies have clients who specialize in feet, hands, legs, lips and bodies. Then send in your portfolio.
Promote yourself. Create a website with samples of your feet in modeling poses.