Buy new shoes if necessary.
Any item that comes in contact with infected foot skin must be cleaned with bleach or other sanitizers. Items like nail tools, shoes, socks or anything that touches your feet. You will probably never want to get athlete's foot again after having invested too much time to treat it.
Use hot water and bleach to wash shoes and clothes to kill fungal foot fungus.
If shoes are too tight, the air cannot circulate inside the shoe, so fungal bacteria are also easier to grow. You can also use sheep wool between your legs to keep them from getting close when you wear shoes. Lamb wool can be found at pharmacies or foot care centers.