Shoes are recommended to be polished every day! You can stick water, but you'd better wipe it with a cloth! And don't wear new shoes on rainy days, they will wear out faster! After a long time, no matter how you maintain it, it will still turn yellow, because it is oxidized ... So when you don't wear it, try to put it in a dry and ventilated place to prolong your life.
Cleaning method: brush with toothpaste, but prepare a clean towel and wipe the foam with a towel immediately! Remember not to use too much water, and then prepare a white shoe polish, of course, the kind of genuine leather maintenance, and apply it evenly on the shoes with a sponge, indicating that the shoes will be as bright as new!
Or you'd better go to a professional shoeshine shop, which will clean and maintain you. Good shoes should be maintained at a professional shoeshine shop regularly.