In modern homes, this is certainly unlikely to be possible due to space limitations, though traditionally, fireplaces were considered to be the best central element to the living room! But it's important to remember that the goal of your living room will 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 space that visitors may well not otherwise enjoy. Mirrors make rooms look larger (and lighter) and very usefully, they will reflect the door, so any seating that cannot face the threshold can still have the door visible through the use of mirrors. Once more, we need to adapt this principle to modern cities and homes, even though the best placement for a mirror is when it can reflect a gorgeous view.