In modern homes, this really is 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 purpose of your living room is going 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 centerpiece 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 also reflect aspects of the space 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 entranceway 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 how it can reflect a wonderful view.