I agree with what's been written about camera angle and lighting, etc....but I would add that you should think about them holistically. Think about the mood you're trying to create, then try to match these elements to the mood or style. For example, once you know the mood, you could start with a camera angle that helps convey it. Once you have the angle, you'll have a better idea of which lighting enhances the mood from that angle, and so on. The lighting coming in through the window is a nice touch in this render, but you'll have to judge whether it works from a different angle. Plus, you may think about where the other light is coming from. Usually, interior incandescent lighting tends to give things a slightly yellow tinge, if you're striving for realism. If you're going more for something evocative or dramatic, perhaps a tint that matches the mood...a chilly blue, a sickly green, an angry red or orange... Once you have those things worked out, you'll have a better idea about whether you need to adjust bumps, textures, or colors. In the context of this render, with this angle and lighting, the problem with the red couch may be that it is sort of a standard red that really sticks out in relation to the other colors and textures in the scene. You could try either darkening the color to match a darker mood, or lightening it to compliment the pink in the woman's shirt. Hope some of that's helpful...still digging your latest gallery piece;-)