T-Rex digital painting

During summer break, I am spending a lot of time working on my digital painting skills.  Here is my most recent work.  I know I still have a long way to go, but I am happy with this as a good step along the way.  As far as looking convincingly three-dimensional and structured, I feel this is a success.  The details could be better.  Also, the lighting could be a lot better.   Here is how I did it.

 Before I started on my own T-Rex, I did a study of another artists T-Rex.  I would have studied photos too, but obviously that wasn't possible in this case.

  First, I sketched the T-Rex.  I focused on giving the sketch three-dimensional structure.  To do this a studied T-Rex fossil skeletons.

Next, I rendered the basic values in greyscale.  I do this so I am not distracted by the colors and can focus only on the form.  However, I did have in mind that the underbelly had a brighter local color.

Then I added a quick color layer.  This is just flat colors on an overlay layer on top of the grey scale layer.

On another solid layer I rendered the forms again in color.  I got most of the colors from the lower layers.  I did use the color picker occasionally but only to augment the colors I already had.   Most of the work is done at this stage.

From here on out, was all adding details.  I also noticed that I didn't have enough dark areas.  Everything was around the same range of value, giving it an unnatural look.  I also noticed that the all the colors were around the same saturation, so just as I added dark areas, I added so desaturated colors to make the saturated colors come forward more.  I finished it off by adding scale texture and details.

I learned a lot from studying the other painting.  Even though I know my T-Rex is much worse than the painting I copied, I still feel as though I improved quite a bit in doing this.  Going forward, I will continue to study other paintings and photos, then try to get a similar result in my own paintings hoping for steady improvement.