Using my original front-view design as inspiration, I begin to apply similar shapes to the character's back, designing as I go but informed by two useful rules of thumb: firstly that costume elements work best when they reflect and flow with the shape of the underlying anatomy and secondly, it helps to establish a visual "language" and stick to it. In this case, my design vocabulary consists of triangles, half-hexagons, and the occasional circle - all geometric forms, in other words. Organic lines would probably feel out of place on this tech-based character.
More surface details. I continue to use the hexagon motif established earlier, as I render the sword and leggings. Recently I've noticed that the hexagon - and particularly hexagon mesh patterns - have become an all too common visual shorthand for the sci-fi genre. I'm deliberately using the shape in a different way here, because I think the standard mesh thing's pretty played-out. If I use a texture overlay during the color phase, I'll definitely go with a different pattern (Fig.05).
Note that it helps to juxtapose areas of dense detail next to areas that are more sparse. This gives the eye a "breather" so to speak, as it moves around the form.
It also helps me focus the viewer's attention where I want it (which, in this case, is her *ahem* shapely behind).
All this time, I've been debating whether to interpret Tech Angel's wings as metal or hard light, and you can tell from the sketch that I originally had feather-like shapes in mind (Fig.06).
Well, at this point, I commit to complex, machine-like forms made of hard light, sort of combining the best of both worlds. I feel like the sword and wings are shaping up to be her coolest, most unique assets, and I want to put a literal spotlight on them. I complete the right leg and arm, but try to leave the line weight and level of detail a little lighter here to help sell the idea that they're further back in space. If you look at the left vs. right wing, you'll notice that I pulled the same trick there. This really helps complete the illusion that one object is closer than another.
All that remains is the face and head. Fortunately, I hit the expression just about right in the sketch phase, and all I really have to do at this point is tighten up the hair and some of the finer details. But because they're so critical let's discuss faces for a moment. For female characters, the important thing to remember is that "less is more." Even a single unnecessary line can age your character 10 years. This means that you have to nail the lines you do put down (Fig.07).
Another thing to keep in mind is that facial expression is one of only two key tools you've got (the other being body language) in communicating a character's state of mind, personality and intent. In this case, the "story" is about strength and, to a lesser extent, sex appeal. She looks back at the viewer as if to say: "Don't mess with me", but you could just as easily read it as: "Hey, eyes up here, buddy."
So there's a little built-in viewer interaction, and that's absolutely vital if you want to engage people. Other strategies for this might include a visual gag, pop culture reference, or just a metric ton of detail - in each case, you're asking the viewer to bring something to the table and to invest some thought in your art, and ultimately, that's what makes a cover memorable.
To see more by David Nakayama, check out Digital Painting Techniques: Volume 4