Hmm its a good start. However the smudging is way too all over the place, you want to try and create some flow, and with smudging like that, it has to really all be in the same sort of direction. There's no real light source, just create a new layer and play around ith a large soft white brush. I think its too big, but thats opinion so ill leave that up to you. Finally try playing with some C4D's and brushes and watch some tuts.
Its a nice start to a sig and i hope you'll keep doing more and improving.