The worlds of illustration and miniatures aren't as far apart as you might think. I actually use a lot of the same techniques in painting as I do in illustration-- one of the most obvious bits is my Object Source Light work:
Both use similar principles of contrasting color and placing light where it would naturally fall. Feeling out how to illustrate lighting was largely based on my earlier work with miniatures, while a lot of my more ambitious color experiments in my paint jobs find their origins in my illustration.
Using pure white edging and glazing as a highlight was completely something from my work in illustration (such as the pic at the top of this post), where I eventually realized that pure white created a more stylized highlight- something I'd avoided for years since mixing white into a highlight generally just makes the color turn pastel.
I think my most successful and ambitious pieces' through-line is how they create a scene or moment. My interest in narrative began as an expansion of my pursuit of photography, where I learned to tell stories in a single moment. This translated into three dimensions in dioramas, and from there to my illustration (The tall bottom panel is probably the most equivalent as a standalone moment.)
Technical elements aside, I (like many people who enjoy the modeling aspect of miniatures) am a big history buff. If it's the light that gives volume and the setting that gives story, then all those specific details can only add up to a strong sense of character. At the end of the day, I'd rather play with--or create--something uniquely characterful than something generically polished.