I think nice art pieces, whether it's one larger piece or possibly two smaller ones would be ur best choice, mainly because it will bring life into the room.

I once found art that I liked but it was to small for the wall, so I painted a sort of border to surround the picture n therefore made it look bigger than it actually was. I chose a paint color that was in the picture. It worked out just fine n I got something I really liked instead of settling for the perfect size.

Do you have some art that you already own? I am not a fan of just buying something to fill the space. I want to see things that I really like! It does not have to be art. It could be objects....baskets, implements, a collection, needlework, framed collections, etc. .

Very nice home ... simple statement and very tasteful. I would suggest one large work of art (hung vertically) and nothing else. Keep it simple, something that works with you room's color palette so not to look chaotic.

Two chairs and art.

Maybe you have too much going on around the fireplace. Try placing the small chest and the chair on that wall just to get a feel for what that might look like.