Your space is nice and colors are good, but it is not cozy and inviting. Start by purchasing an area rug for color and pattern. It should be large enough for all the front feet to sit on. Your window casings are nice so you may not want to cover them with drapery. Add some stationary faux roman shades at the top. Put the bookcase on the wall where the chair is now, so you can center the sofa on its wall. It is OK for the other wing of it to be away from the wall because it will actually make your space appear larger than it is. Pull the chair up onto the rug so people can carry on a conversation, and add a round coffee table and a small side table for the chair. The chair can be pulled back by the bookcase and lamp if you want a reading nook. Style the bookcase with 1/3 books, 1/3 decor and 1/3 open space. Your wall items are all hung too high. Mirrors are only useful if they reflect a beautiful or interesting item like a chandelier or a view, so I prefer art. You could leave the three small mirrors where they are but the top and bottom ones need to move up and down so they are much closer to the middle one. That middle one should have its center about 60" above the floor as should any piece not hanging over furniture. Pieces hanging over furniture should be 5-8" it.