Well I've got a few gigs to catch up on at the moment. One is doing aliens in my messy alchemy style, and the other is sci-fi race bikes. But I'm planning on doing the bomber drone next After that I might post a few messy sketches of civilian variations and I'll try to move on to other machines or creatures from this little universe I'm working on.
You've got some impressive vehicle design going on in a few of these pieces, but I would back off of the dodge/burn tools. They're a fallback that should not be used 90% of the time, light and shadow are not defined by white and black, rather, light is always colored (in many cases, yellow-orange, but almost always a warm color) and shadow is always the complimentary color of the light (almost always a cool color, like blues or purples.)
So a fairly common lighting set up might be one of yellow hued light, contrasted by the purple tint of the shadow. This doesn't mean that the light or shadow is obviously colored, you can tone it down a lot, but simply putting it in there will really add a spark of color and depth to the work that isn't necessarily there at the moment.
Hefty assumption there I never used the burn and dodge tools on this piece. But I did paint the body in greyscale.
I understand what you mean about light never being pure white. . . something I should have remembered from my color theory class But thanks for both the reminder and the feedback! I won't forget about on my next piece. might even go back and toy with this one a bit later.
My assumption might have been incorrect, but thats simply because the greyscale shading you see in so many pieces that use it are the most obvious symptom. Eventually you might want to start working with a base or local color for your work, just a color that the ship would be in totally neutral lighting, and then work the color of the light and shadow into it. Starting off with neutrally colors and adding light+shadow to it is certainly a good way to start off.