Well its cool using mental ray, you need to understand light souces a bit more.
Overall you aren't doing this model any justice. Stop for a minute and have a think about whats missing...a strong light source from a window would do this shot the world of good, also a different camera angle and a reshuffle of the furniture. Its a bland looking image, its shot straight from the front making it flat.
Put a strong spotlight coming from one direction only which will then help to pick out the edges of objects, then use FG to help fill out the rest of the objects. Its not a case of being a Pro, its a case of looking and understanding whats around you. Practice on something as simple as a sphere with a spotlight with a hi intensity and another on lo, without the use of MR, move them around and even give them a diffent color for ambience etc.
The book Digital Lighting and Rendering by Jeremy Birn is a must have for understanding light concepts