Wash them frequently, air out your shoes (don't wear the same pair two days running) scrub dead skin with pumice and maybe try an anti bacterial (like tea tree oil) or a foot powder, also stick to cotton socks - not nylon.
antibacterial soaps (DIAL is a good brand), as well as epsom salt foot baths. it will make your feet less moist and will provide less of an environment for bacteria to form and grow, and you should be careful because that can very easily escalate into athletes foot. those are some macgyver-find-stuff-around-the-house methods but hey i hope they work for you
What AJ_Drose and TieGuy have suggested is good. Be sure to wash and dry your feet daily. Use a foot powder between your toes to absorb excess moisture. You can deodorize your shoes by sprinkling some baking soda inside them at night and lightly stuffing them with crumbled newspaper.