This is one of my favorite posts I have done since we started our blog. This post is one of our most searched on Google. I refresh mine every three or four months. They are so effective and less expensive than purchased air fresheners. I love experimenting with different scents for each room of the house.To do this project you need a small mason jar, cheesecloth, baking soda and essential oil. Essential oil can be purchased at craft stores and health food stores. I got mine at GNC. Just spoon about an inch of baking soda into the mason jar and add 8 to 10 drops of essential oil. Cover the lid with cheesecloth and screw on the band. Trim away any excess cheesecloth. Tie a ribbon around the band, or pop it into an pretty organza bag like I did. You can see the original post here.