Be a very wary bear!
I have had some requests to explain how I create me pieces and the answer is: "Depends". I change up what I do based on what type of piece I'm making. So I thought I would create one piece with two different methods to illustrate the methods I primarily work in. So this piece will be done in both watercolor and Photoshop. As you'll see they start the same but end differently.
I first start off with a sketch:
This is where the methods diverge.
In the watercolor I find it helpful to lay the shadow first. If I try to add the shadows after the color it tends to have very unnatural blotches.
The final step for the Photoshop is to add shading and Highlights. This was a quick rendering as I intended this piece for watercolor. But using more that one shading/highlight would deepen the detail. For a photo-realistic piece I will sometimes spend upwards of 4 hours just doing the shading.
So there you have it. One picture with two different methods. Each method has its advantages and disadvantages. The water color tends to be quicker and easier but it is far less forgiving. The Photoshop is time consuming but very forgiving. But that's pretty much it. No real "magic" just practice and time. Anyway I hope this answers the questions but if anyone has anymore don't hesitate to ask.