Watercolor and Canvas in Photoshop

Because I can’t seem to find any tutorials, or topics that don’t have to do with “Making a Photograph look Watercolored”, I’m posting here, and hoping for the best.

If anyone has happened to flip through the book by Brady Games called “The Art of Final Fantasy 9”, illustrated by Amano himself, you’ll know what I’m looking for.

Basically, I want to be able to take a hand-drawn image of say, a weapon, or something, and clean it up so that it’s just lines, and paint in Photoshop in a way so that it looks like it was done in watercolor, or something similar (perhaps colored pencils on wet-canvas), with a bit of canvas texture going on. I can pull of a semi-decent version of it like the image attached (which was made in a rush), but I was hoping that someone might know how to pull of the effect much, much better…
Any help would be greatly appreciated!