Joy4uall:
I’ve seen your designs on Coroflot page. I would not have much to say, because they are very good. Just one thing, beware of the black, not always used the black to give depth, volume or just shadows. Sometimes you can provide depth in an area, simply by reducing the saturation of the color and amount of light, with no need to splice a dab of black above the surface. It is good to use touches of black when the design environment is very dark. But the backgrounds of your designs are white. If you want to do even more artistic renderings, you can try that, but if you already work professionally and you get good results, your work is excellent.
Greetings.