Love it! Maybe you can put one color accent (with 1 pillow) depending on colors you already have in the room. Browse Houzz rooms in order to find ideas for your artwork.

That depends on the rest of the room (and house), especially other fabrics, such as window treatments and rugs.

Lots of examples when I search for wood floor and black sofa: http://www.houzz.com/photos/living/%2B%22wood-floor%22-%2B%22black-sofa%22-

I love your sofa,where did you get it from?:-).
Also. You may add some colors such as turquoise, orange, mustard..

Check out Etsy.com for artwork.

Kat Shoa has a shop there and I love her work!
https://www.etsy.com/shop/KatShoa?page=4

Thank you everyone!

We've got white plantation shutters but the rest of the house is pretty bare as we only recently moved in. No rugs either.

The sofa was custom made for us locally, here in Australia :)

Facing the sofa we have white gloss tv unit.

How many more cushions do I need? :)

4, or else you would have to drop them somewhere when you want to sit on the sofa ;)

A pop of your favorite with throws and pillows. A big soft fluffy rug under the feet and a pretty glass coffee table on top of that!

Definitely start with a rug. I don't know what your style is so can't make specific rug suggestion. But, I would take advantage of this neutral palette to choose a rug with a design and colors I love, then add pillows and accessories repeating those colors. Make sure the rug is large enough to be in scale with the sofa. The sofa has pretty hard lines, you might consider a round ottoman out of fabric. Above the sofa you could do artwork in graphic black and white, or color. Don't worry about everything matching. I am a believer that artwork is chosen because you love the piece. It should stand out in the room if you made the decision to invest in something. Check out local colleges the art department has several sales during the year of student art; especially around this time of year. Once you have the rug and ottoman add some chairs for additional seating. Enjoy and have fun.

Citrus yellow

Wow. You guys are amazing!!! I cannot thank you enough!