Bed sheets should be washed at least every other week. If you sweat at night, wash your bed sheets weekly. On the other hand, you only need to clean pillows and comforters 2 or 3 times a year. An easy reminder: Wash them when the seasons change.
Of course, after someone's been sick, throw all their bed linens in the washer.
When it comes to bathroom towels, they need a spin in the washer after 3 or 4 uses. To keep towels from getting musty-smelling in between washes, make sure to hang them up and give them room to air dry thoroughly. Towels that are used after a workout need to be washed more often.
In addition, if your bathroom sees heavy foot traffic, the bath mat may need to be washed weekly.