If you have a fake Christams tree and miss the aroma of a fresh tree, here is a holiday room spray from Allison B. Kontur (http://www.bathbodysupply.com/).
4 oz Liquid Perfume Base
5 ml (1 tsp) Fir Needle (White/Silver) Essential Oil
4 oz PET Boston Round
20/410 Fine Mist Sprayer-Black
Combine ingredients in bottle. Cap and shake well to blend.
To use: Spray liberally into air.