Clean your fan as you would any other household electrical appliance. Use a soft dry cloth to lightly remove dust and debris at least every 3 months.
Built-up grime such as pet dander or dirt caused by moisture will cause metal parts especially blades to corrode or rust. Regularly remove grime with a dampened (not wet) cloth and dry afterwards.
In humid climates, air conditioning will make the fan blades cold and when warm/humid air enters the room it will cause moisture to condense on the fan blades. This may cause dirt and corrosion to form more quickly.