One of my favorites:
Give your room a fresh scent. Whip up a room deodorizer on the stovetop by simmering orange rinds or lemon slices and rosemary in a pot of water. The scent will freshen your space.
Soak a cotton ball with essential oils and toss it under the bathroom sink (out of reach from pets) for a clean, fresh smell. Try lavender, jasmine, or any fragrance you like. The cotton will stay fragrant for about two weeks.