My experiment- A pastel on watercolor paper

Here's my latest pastel painting.  I was really excited to work on this one since I loved the photo so much.  I have to admit I'm a little underwhelmed.  Part of the problem was the paper- it was on watercolor paper not traditional sanded pastel paper.  I was trying a technique I read about in a book that suggested doing an underpainting of watercolors and layering the pastels over.  It's hard to tell in the painting that there's even an underpainting there.  I'm not totally sold on the idea of an underpainting but maybe it's just me.  So far I have yet to be impressed, and in fact I think I prefer the immediacy of just getting right to it.  Sometimes I try so hard to follow different sets of rules that I forget how to just go with my natural instinct as an artist. What bothered me most was that there really is no tooth to the paper which made it impossible to layer colors.  I think I will try different paper next time.