Wash your feet well, and dry them thoroughly.
Keep your feet clean and exposed as much as reasonable, as in don’t wear socks or slippers around the house, wear sandals if possible during normal day to day life.
If you must wear socks and closed toe shoes, change your socks several times during the day, and let your shoes air out when you’re not wearing them.

Apply an over the counter nail antifungal regularly.
Be patient.
Trim the nails regularly.