Still not quite where I want to be...

But I can see it from here.

Thought I'd try mixing it up a little, doing the initial outlines in Inkscape and doing the color and shading in the GIMP. Overall, I'd say it worked out pretty well.

Bear in mind that what I'm doing here are basically quick sketches done off the top of my head. As things progress, I'm sure I'll be delving into more complex stuff, but right now this is just me stretching new muscles. Some rather hapless spasms are to be expected.

What to fix: The bucket fill is leaving some unpleasant-looking edging between the fill area and the black lines (time to hit the GIMP forums, I suppose). Of course, I have to watch my perspective and be a little more thorough when erasing unwanted lines and overspill from the shading.

Ah, well. Time and patience. Hopefully, I'll have enough of both.