That's pretty good. You've demonstrated here a skill few are willing to build and develope, with some quality behind it. In time, you'll get a better hang of it as you learn new techniques.

Many of my early attempts at realism were built on starting with dark colors, then adding lighter and brighter colors over that, when in reality it looks beter when you repeatedly add lights over darks, and darks over lights in all the right spots with finer details until you get a better result.