Your living room has a great color scheme, cozy fireplace, and a large window providing natural light.
We also love your very current color scheme with the browns and blues.
These are some suggestions that will maximize space and help create more cohesiveness throughout.
1) The sectional sofa is a beautiful piece, but is rather large for the space. We suggest breaking the sectional up into two smaller pieces, placing the smaller of the two pieces under the window and the larger piece facing the fireplace. This will allow easier movement in and out of the room, and make the room feel more open and spacious.
2)Mount the TV over the fireplace, and move the existing piece of artwork to another location.
3) Lamps or lighting are needed in the room. Moving the TV will give you enough space for an additional end table and lamp.
4)Consider purchasing the MyDesignGuide Art and Accessories Service! We will identify the exact pieces of artwork, accessories and lighting that will finish your room. We love the sofa pillows and would select art, lighting and accessories to help you coordinate with these and your room style. We have already found a few that are fantastic!
5) If possible, remove the wallpaper and paint wall the same color as the rest of the room. If the wallpaper is in good condition you can just remove the border at top and paint over the wallpaper (prime first!) This wall needs additional art too, of the right scale.
6)Consider moving the ottoman to the center of room to use as a coffee table. This gives your ottoman more versatility and provides you with a coffee table using your existing furniture. 
