I’ll show you how to do the simplest blending.
The principles apply to almost any surface, but this method is most effective on small surfaces.
You should think about it like the 3 step process. Dark base colour, bright midtone and almost white highlight.
However, don’t be to attached to it because each step can be broken into smaller steps.
Just use it as the point of reference when you plan your work.
Hope it was helpful. Let me know about your results.