The round mirror is already enough for the mantel. I'd clear off the little screen and most of the small pieces, then keep one low object on each side, maybe two chunky candlesticks and a small plant. For the TV wall, a long low wood console would help anchor the screen and hide those outlets. Put it a little wider than the TV, then add one tall plant or floor lamp on the open right side. I wouldn't add wall art there; the fireplace side already has plenty going on.

Thanks Alex! All great suggestions!

I’d treat the fireplace and TV wall as one connected area rather than decorating them separately. The round mirror is beautiful and distinctive enough to be the main feature above the fireplace. I would remove the greenery beneath it and let the mirror stand on its own, perhaps adding just one simple object at each end of the mantel. Under the TV, I’d place a long, low console in a warm brown wood that works with the leather furniture and coffee table. A tall plant beside the console would add height and soften the empty wall without competing with the fireplace.

This video shows how the same living room can feel completely different just by changing the lighting, colors, materials, and a few statement elements. It may help you decide which overall direction you want before choosing pieces for these two walls:

https://youtu.be/R-2ZyyBc6EY

Thanks for your ideas!!