If you just keep studying the 'science' side of art (perspective, anatomy, coloring etc.) then you'll definitely draw like this in no time at all. Keep drawing everyday and read into these sort of things. It's really simple once you have the hang of everything. I'm not saying that I'm particularly good at the moment nor could I draw something like this right now, but all in all, it's not that hard.
Just keep practicing. It's not one of those "maybe in ten years, you'll be blah blah"-- it's more like, "maybe in a year, or six months". Depends how efficiently you work.
Amazing details. I love the way you can see the color of her bra through her shirt. Also, the no pistols sticker is pretty funny. I don't know who she is, but a girl with a shotgun and a cigar has to be taken seriously.
Wow, amazingly beautiful hair and face and I like the shark jaws sleeve, lol. Especially love the way you did the alligator skin stuff. The spurs look cool, too. And the anti-gun sticker on the gun is ironic. XD Love all the details!