keep making more! watch your highlights. you'll want to have just one main highlight and the rest will not be as bright. and try not to use straight white. having the same value highlight on both shoulders flattens it out.
i usually don't connect some one writing about how to paint to the canvas but I got a great book that actually does the trick to help you help yourself. Its called ALLA PRIMA; Everything I Know About Painting by Richard Schmid. A great book if you can pick up a copy. I think Donato had it at the gallery studio last June.