Most of the time I make separate layers for color flats, shadows (with multiply-blending), highlights and line-work on top of everything else. Backgrounds basically get split up in a similar way, though often times go with a reduced layer set (e.g. no lines, like in the pic above). My coloring is pretty straight forward in most pics: flat base colors that get overlayed with shadow shapes (which can be filled with flat-colors or gradients). And usually I use one shadow color (and/or one base gradient) throughout the entire picture. Not sure what else to say here as there's really no "special magic" taking place. I hope this answers your question nonetheless.
Yay.. cool! I'm glad my works are an inspiration to you. And yes, this (and a lot more!) can be done in Inkscape. You can get pretty far with just trial & error (my preferred way of working xD). And there's lots of tutorials and helpful people on the forums. So yeah, there's absolutely no reason to give up hope
Wow That is very beautiful. I love the use of colours and the shading is great. I especially like the subtle red smears on the figure, a nice touch indeed. Just curious, how long roughly did it take you to do? Because that time paid off
The blood/dirt/scratches were added to make things look less clean/smooth/vector-ish. I guess I could have added a lot more than just these few details.. but hey, there'll always be a next pic that can be done better xD Glad you like it anyway ^^
As for the time it took... Hmm, that's hard to tell. Usually I need roughly a week per image, on and off, depending on how much other non-art work needs to be done. Maybe 20-30 hours or so; I'm rather slow and I'm working with mouse, not tablet. Not sure if the results really pay off for the amount of time I need to spend on my little pics xD