Final answer:
Return the unused pillowcase to the linen supply to ensure good resource management and maintain hygiene in the resident's environment.
Step-by-step explanation:
If you brought 2 pillowcases into a resident's room and the person uses only 1 pillow, you should return the other pillowcase to the linen supply. This practice adheres to proper resource management and maintains the cleanliness and organization of the resident's environment. It is not considered hygienic or appropriate to leave it in the person's room for another time, take it to another resident's room, or put it with the dirty laundry as it is still clean and unused.