Great room, wish I had too much room. You need to move the couch away from the corner and the window wall, at least 3 to 4 inches. That will also line it up with the fireplace. A large entertainment center will make that wall. Maybe a bar or library in the niche. I think a game table or farm table would be great for teenagers just to hang at.

Install glass shelves in the niche with and LED can light in the ceiling of it to light up a collection of something pretty, interesting or unusual. This is is a very awkward arrangement with the sectional jammed in the corner and into the windows. With the larger TV centered on its wall, you'll need to pull the sofa out to float centered with the TV wall and the fireplace. You might try its matching hassock/footstool pushed into that window corner with a pile of colorful pillows to match a new rug. That would make a nice reading spot or a corner lounge for the teen who wants to be on their phone or other device. Your rug is much too small for that big sofa. That's where you will get the "homely & warm" color/pattern. Once you get the furniture arranged, use painter's tape on the floor and tape out a "virtual" rug that slips under the front 1/3 of the sofa seats and extends past the ends of it by a foot or more. Keep it at least 12" from the hearth. If your measurement is not a standard size, then go up a size if you can so you don't get a skimpy one. As for empty space around the sofa, try a sofa or game table behind the short side of it. If you're not installing draperies, hang art between the windows. You can put casegoods under the art too. The art above the mantel is too large; keep it mantel art within the width of the firebox below it.

There are other colors besides brown. Some light area rugs, LARGE.... a sofa other than brown leather, better lighting to include lamps.Do the space for YOU. Teens will hide in their rooms, they will search the privacy out, It is the nature of the cave dwelling teen. Stopping that is like trying to stop rain. The tv used to draw them out. Less so today as they never are off their phones. That is the new "TV." Even when in front of a tv.....they are on the phone.

Food is your only recourse. And making them eat it in front of you. Otherwise, that food will go the "cave"

Here are a few ways to help brighten your family room. It looks like your entertainment wall could use some sprucing up, so you could easily try getting a new TV console in a color that might work in your space and add book shelves to the space. Also a new rug and window treatments. See our design in photo three? Then what about adding a pool table or a bar to the back part of the room since you have so much extra space?

You can always incorporate a large opening and have that indoor/outdoor feel to you living room.