The basement is commonly carpeted for a cozy feeling usually in a tan or beige color.

Daybeds looks very nice in white, beige, and yellow. Daybeds look even nicer next to windows.              

As I said before light colors or pastels look awesome! Colors such as beige, a creamy white, or yellow are often found in basements. 

If you are going for a romantic look a mantel over a fireplace with candles on it, is the way to go. If you don't like the idea of the candles than try some family pictures. It is best to put couches in front of windows opposite of fireplaces. The fireplace will make the room look nicer and more roomy. Chandeliers might be a little too fancy so don't go that far!

Wood furnishings are really nice, and there are many different stains of wood so you can find the stain color that matches best. 

If you are using your basement as a study make sure you have books! It will make the room look more interesting. 

Draperies can really brighten the room. Draperies are used to keep the sun out, shade the room, and privacy. Some times they are just used for decoration. 

If your basement is looking kind of dark and gloomy try many lights of different style! Also make some hang down and some on a table top.