How about moving the chair to where the ottoman is, use the lamp on the end table by the couch. Use the ottoman with a tray on it for the coffee table. You need a taller piece of furniture under the TV. Is that a buffet in the dinning area, could it move to the living room? I would use the curio cabinet to separate the living and dining areas. I see word art by the door and in the dining room, you could group them on the TV wall. Throw pillows and throws to coordinate with the drapes. You could also add an area rug to anchor the space and another pop of color. The mirror on the stair wall is serving no purpose in that location. It and the coffee table need new homes. It is a great space, I am sure it will all come together. Just use bits and pieces of the advice that fits you. Good luck and post an after photo so we can all see what you come up with.