Originally Posted by
Vicious Zen
Shading is not an easy thing to do with vectoring. You've gotta do it all manually, it's not really something a tut can teach you. You just have to play with the colors. Something I've done, which you could try is use some low opacity gradient filled layers. Just use a black gradient overlay that fades to transparent, set your layers fill to 0%, and play with the opacity from there. Either that, or just use solid shadows, but you're just gonna have to play with the coloring of that on your own if you so choose.
It's a really good start, I'd definitely finish it if I were you. Love the BG, and your colors overall. Very good work.