You are taking a portrait of the little clay person and portrait lighting would really improve the result. Move your main light about 30 degrees to the right and add a fill light of about half the intensity close to the camera position.
There are lots of good book and I'm sure web tutorials on lighting. Any light you can move around can work just don't mix bulb types or the colours will get weird. In PhotoShop you can do a Select - Color Range on the yellow and then modify it with Levels, or Curves, or Hue Saturation. Powell
