While this is directly associated with foot deodorizers, it is a fitting question. Even though foot odor is more or less inevitable, there are some tips you can follow to prevent it as much as possible (in conjunction with any shoe deodorizer). For starters, ensure that you are thoroughly cleaning your feet every single day. Yes, this means getting in-between your toes and scrubbing with an antibacterial soap.
Past this, you also may want to invest in a pair of highly-breathable shoes. When your feet are not allowed to breathe, moisture builds-up and eventually, this will lead to a potent odor that will kill off everyone and their mothers. Take this into consideration with the socks you wear, as well. Socks that are crafted from materials that wick away moisture are also beneficial. But, with all this said, it is still highly recommended to regularly deodorize your shoes.