I found various recipes for natural air fresheners involving rosemary, lavender, cloves, etc... but I decided to go with what I had on hand.
A sauce pot, 2/3 full of water
1 lemon, cut up into slices
2 cinnamon sticks
1 capful (about 1 tsp) of vanilla extract
I set the pot to boil, then after it was boiled, I added the ingredients. I reduced it to simmer, and through the day, I would add a cupful of water, when I saw it was getting low.
Kept it going all day, and the entire condo smelled incredible! My agent even mentioned it as soon as she walked in the door. This scent is absolutely heavenly, and I definitely recommend it. If you search around pinterest, you'll also be able to find various recipes for different scents. Here is the recipe that originally inspired me! Let me know in the comments if you have a wonderful combination that makes your house smell divine.