From a "classical" artist's point of view, Photoshop is cheating. You are not bound by the limitations of any medium, such as pencil grain or lack of opacity or inability to blend. Photoshop gives you all the possibilities of media at once. The only thing it doesn't give you is texture and simple portability (other than prints). And I am not that concerned with that.
But classically, it should have been done in oil paint, while I was sitting outside. It wasn't even raining. Plein air, for Ghod's sake, like a real artist, not a screen-bound photoshop nerd.