In modern homes, this can be unlikely to be possible due to space limitations, though traditionally, fireplaces were considered to be the optimal central element to a living room! But it's important to remember that the objective of your living room is to be inviting to people, to obtain them to feel comfortable and relaxed, and stimulate good conversation. So, even without a central fireplace, making the fireplace some sort of center point will also work well. Mirrors are a wonderful tool to enhance Feng Shui in a living room. They bring light into darker areas and can reflect aspects of the area that visitors may well not otherwise enjoy. Mirrors make rooms look larger (and lighter) and very usefully, they may reflect the door, so any seating that cannot face the threshold can still have the door visible through the use of mirrors. Yet again, we need to adapt this principle to modern homes and cities, even though the best placement for a mirror is where it can reflect a beautiful view.