I usually only make this around the Thanksgiving and Christmas holiday but hubbie LOVES the smell.
1 orange (I used clementines, since it's what we've been eating lately)
3-4 Cinnamon sticks
1 teaspoon or so of whole cloves (about 8-10)
Slice the orange, don't worry about peeling it. Place everything in a small pot with about 1 1/2 cups of water. Let simmer on the stove, on a low temp for the rest of the day. Don't forget to add water every now and then, since the water will eventually evaporate.
My potpourri usually can last for about 4-5 days.
P.S. Cinnamon sticks can be expensive if you purchase them at the grocery store. I bought this bag at the dollar store.