When I'm reading, I don't really create a mental image of characters. I will pick up on vague things, like this one is blonde and that one has olive-toned skin, but I don't actually sit down and wonder exactly what I think the character should look like. This is one reason I never get bothered by actor choices in movie adaptations of books I've read, because I'm perfectly content to be given someone else's interpretation of the character. After all, I have no stake in it, no vested interest.
When it comes to my own characters, this doesn't hold true. In most cases, I will draw them out before I create a worksheet for them, and they exist in my head in a fully-fleshed out form. Getting this image onto paper or screen is challenging, and doesn't necessarily work out, usually due to my own skill level and the difficulty of what I'm trying to attempt. However, yesterday, I was trying to iron out a historically-equivalent era to set The Brightest Night, and settled on early Medieval, except they have stirrups, which means they have hard-soled shoes. (On a side note, there's a fun argument that the invention of the stirrup led to the creation of knights, and since knights/horses are expensive, led to the feudal system.) I also decided that the spindle and horizontal loom had been invented, and that trade routes to other lands that produced silk and velvet had been established, to allow for greater diversity in pattern and material in clothing.
After establishing this, I went to my go-to doodle fuel: women's clothing. In this particular case, noble women. At some point I will figure out regional variations, but for the moment, enjoy my sketch:
At that point, I started wondering if I should draw Riley and Kael. I've painted them before (some few blog posts back), and it was very, very close to what I imagine them to look like (except that Riley came out looking a lot older than I intended). So I tried. Again, it's not exactly what they look like in my head, but it's so close that I will say that it's them.