Adding rugs definitely makes the 3D view feel more 'homey.' One thing I’ve started doing is picking out the actual rug I want first so the colors in the render are accurate.

I’ve been using some of the transitional patterns from Dash & Albert Rugs lately—you can just save the top-down view of the rug and import it as a 'User defined' texture in Sweet Home 3D. It makes a huge difference in the final lighting of the room when the rug texture looks authentic.