You probably will want your living room to have as much light and sunshine as possible. Study the quality of the natural light and judge how much your windows provide. What are your exposures? How many windows do you have, and how large are they? (The more windows and the bigger they are, the more expensive they will be to cover—which may very well stop you in your tracks and direct you to a more simplified window treatment.)
If you love curtains, then have beautiful windows warmed by materials you like. My only suggestion is that you keep the curtains straightforward. Elaborate window dressings—heavey draperies and valances—seem outdated in most rooms today and are expensive dust catchers, (this also applies to the door hardware throughout your house), which has most likely been painted many times over, and send them out to be cleaned and restored to their original shiny brass condition.
When deciding which curtain style to choose, consider what you want them to do for the room. If you want to add color, warmth, pattern, or spark to an awkward window situation, try straight-hanging lined panels with ample fullness (so they look generous) with an interesting heading (the way in which the material is gathered at the top to give it fullness). You might also think about taking an entirely different route by using shades.
Often, window treatments are an afterthought, but they are the design element that truly pulls a room together. Window treatments separate professionally designed rooms from the rest and should never be an afterthought.