Thread your twine through the hole in the wood ornament and tie it to make a loop. If there is no pre-drilled hold, you can make one using a hammer and nail.
Add carrier oil to a small glass or ceramic bowl
Stir in 15 drops of essential oil
Using a small paintbrush, paint the oil mixture onto a wood ornament
Place the ornament into a Ziploc bag and allow the oil to absorb for several hours (or overnight)
Remove the car freshener from the bag and hang in your car
To renew the scent, simply add a couple drops of essential oil directly to the ornament