Learning to paint, looking for techniques and tips!

[OrangeCatNinja]

http://ocninja.iwarp.com/images/paint/safari01.jpg
safari dude

http://ocninja.iwarp.com/images/paint/samus.jpg
samus aran

that's what i've done so far, both in Painter.
I'm just looking to see what some of you folks think i should do to improve, i've just sorta been feeling my way around, need a bit more of a direction to push ;)

thanks!

[AnarchyAo2]

The only thing i can complain about is the jaw line. Theres light were there should be shadow.

[dindon]

maybe a green glow on her jaw from the little green lights...?