I don't have much experience with soft pastels, and I'm still getting used to them. I have used oil pastels in the past and just loved them. I'm finding that I'm loving soft pastels as well. Once you get past the mess that they make, they're a lot of fun.
So after leaving the painting for a while and going back to it I can tell it needs some more darks. I think if I just darken the darkest values, that should do it. It could also use some other small changes.
I'm feeling like I'm not all that prepared to complete a pastel painting because I don't have all the supplies that I need. All I have are a few sets of Sennelier Pastels, no pastel pencils, blenders, or brushes. So, doing detail is pretty much out of the question, until I purchase these supplies. But I have enough to play around, and that's what I'm doing! :)
Just a little reminder - For the next couple weeks in my Etsy shop, I will be donating 100% of every sale to the American Red Cross to help those in Haiti. If you were going to donate anyway, this is a great way, because you get a little something for doing it!