I don't remember where I got this idea, but I know it works and works really well.
To make your house smell amazing without ever spraying anything into the air or having to worry about unattended scented candles, just do this:
Go to the local dollar store and pick up a bunch of these. If you'd rather pay full price, you can get them just about anywhere.
They come in a large variety of scents, so just pick the one you like best. I prefer Vanillaroma, and everyone who walks into the house in the last week goes "ohhhh, what's that smell!??"
Remove one or more floor heat registers, and either hook one on the inside or just clip it on to let it dangle on the inside. Replace the register and just wait for the furnace blower to come on.
Voila, your house smells great, it's not overpowering, and these little tree fresheners last about 2 weeks. Try a different scent in the spring/summer months and when your central air comes on, the house will smell like a tropical island or a cool mountain stream! :-)
If you have a Cheap & Easy Homecare tip, please feel free to leave a comment and tell me about it!