One of my favorite things to do in the winter is to have a crock pot going with homemade potpourri. In the winter, with the house all closed up, the air just seems to be stale. I think I should have lived closer to the equator so I could have my house open all the time.
The best way to give the air a little lift, is with simmering potpourri. I cut up whatever fruit I have on hand - apples, oranges, grapefruit, lemons, lime... whatever. I throw in a stick of cinnamon, cloves and any other spices I am in the mood for. Then I just make sure that I add a little water from time to time. It sure does smell nice!