I agree with all of the points made by Kathy. Move that rug to the bedroom or kitchen and buy something definitely larger and warmer... lusher and of a natural fiber. I would remove one leather item, perhaps the chair, to the bedroom and replace with something softer or brighter. A bit too much matching going on Sweetie. Doesn't make each piece feel special enough. Love your wall colour and the colours in your one piece of art. You have given us a peak into what you like with these. Bring in lots more of those colours and find more art in a related family and arrange a grouping, not one piece here and one piece there, and, as Kathy said... Lower! You also don't need to limit yourself to paintings on the wall, all kinds of things can be put there. I have brass trays, antique fabrics, wooden corbels, sconces and more.

The curtains that Jacqueline posted are beautiful!!! Something like that would go a long way to warm up your space and make it feel like a home not just a room where furniture is stored.

Next, you need to fiddle with the furniture arrangement. I would start by putting the long sofa on the longest wall and work from there.

Lastly, I don't know where you live, but most towns have a section with lots of antique or "junk" stores. I love the "junk". Why not take a couple of Saturdays and go for a stroll thru a bunch of these places and see what catches your eye. It could be an old frame or window, an antique box or beat up statue, an old piece of metal... almost anything with some personality. Find something quirky that speaks to you and bring it home. Your house will immediately feel differently. It will feel like you. And when your friends come over they will see and feel you in the space. Auctions are also a fun way to find unusual things for the home... at really good prices.

The point is have fun, be yourself, express yourself, buy only what you love and it will all work. Can't wait to see what you discover.