As for the plasticy look...the leaves were freshly washed
Ahhh. That explains the washer then. 
Some leaves actually do look plasticy like that, so you're not too far off on that.
The light is way too bright though. Or perhaps, it's the lack of any detail outside the window. The contrast is just killing the image. Put in some outside area and it should bring it all together.
Dave Baer
Professor of Digital Arts
Digital Media Arts College
Boca Raton, Florida
dbaer@dmac.edu