You need objects that are taller and more solid to stand out. Pick two or three colors you love and look for objects in those colors. Is there another spot for the t.v. so you can put a pretty piece of art work above the fireplace?

As the shelves seem to be too shallow for anything substantial, just remove them and resheet rock and paint the wall, then design something that will work with your wall and room.

Don't burn candles on those shelves is my first advice! I can't even imagine how many articles have been written on this very subject of styling shelves. And just as many theories. What you have now is about all the same size and color. Vary that. Move your plant over to the left some and put the bird next to it. Find a small piece of framed art you have and put it on the next shelf against the back right in the middle. Repeat on other shelves & don't over do it. Scan Pinterest for ideas. Post your changes!!

Potted mini succulents? Air plants in small glass containers?

I would paint the same color as the wall, remove the shelves and put a tall statue on each side. OR I would get two long,skinny paintings and just cover that area with art.

Sometimes you just have to eliminate the problem entirely. I agree with Susan that the shelves need to go and you will be free of the problem.

Personally, I'd take out the shelves and put complementary (don't have to be matching/identical pieces) tall/structural sculptures. It will make for a more modern feel. If you stick with the current shelves, then get rid of the scrolled edge (which is really dating).

Oh, since you are hanging the TV over the fireplace, I'd also add lighting to the top of each "art alcove" for a nice effect.

I would do this

Paint the mantel white as well .

Wreck shelves then put white tile inside then install glass shelf inside. On first part, put a long flower in on top shelf then in lower shelf put a couple of storage boxes. On second part, put on top shelf a metallic horse structure. On the lower shelf put a photo in a small photo frame. Paint walls light yellow. Install in the upper part of the fireplace white and gray marble.Take off the glass then put a fireplace cover which is gold geometric shapes. Put next to the TV some small paintings.

Thank you all for the help. I will try these ideas they are wonderful. Until I can convince my husband to take the time and remove the built in's.