This one is for

because she requested it.

I'm not really qualified to do a tutorial. That's something someone like Andree Wallin or ukitakumuki would be good for hehe, but this is the process I use. The art director where I work taught it to me.
this exercise is designed to help you to get flexible with tones, colors, and lighting under pressure so that you can get your thoughts out on 'canvas' with confidence when it matters.
i hope this is helpful!
just retouch it up a bit more
ps. love the rock texture and colour...it's quite polished up here
Looks great, of course!
the result is amazing, and im might have to try those brushes