Lovely room. I'd first see if you can trick the eye to not look up to the ledge.

1. Paint the trim on the ledge the same color as the walls instead of the current trim color it is now.

2. The three pieces of art hung extremely high on the wall draws my attention straight to the ledge. I'd consider removing that art. (Though I assume you like it there and may have even purchased it for that space.)

3. Place a bright green floor plant to the left of the TV console. It may help to bring your eye close to the midground and base of the room and take some of the attention off of the high up background.

Try buying the colored rug first. That may direct attention more downward instead of up toward the ledge.

Some inspro

Adding drywall to close up the ledge should not be too expensive and will look great. Most drywallers use a sander with a dust collection bag to keep the dust to a minimum.

Adding a chandelier and picture lights as shown by @Celery. Visualization, Rendering images will also look great.

Maybe add a plant or two like a tree next to the TV stand.

The art over the TV is hung way too high so consider relocating it.

Please add after photos!

I would probably demo everything around the fireplace and reclaim as much depth as I could. I would want to be using more of the height too. The built-ins could be wider and taller without all that drywall surrounding them.

Why pay for tall walls and then decorate like you have 8 ft walls!

Not quite the same, but to show how you can be creative with high ceilings.

Amity Worrel - Barton Hills · More Info

The proportions on the elements in this room are a bit wonky.