This looks great! Just curious, how do you create that vapor? It looks like a fire/flame texture. Do you use a texture and change it's shape to fit your piece or did you create it completely from scratch?
If I remember right I started with a texture, I think it was smoke, but didn't really like the way it flowed in relationship with the rest of the piece so I had to paint it quite a bit. It's pretty simple if you start with a soft round brush and erase back edges with a hard edged eraser or lasso tool. Use plenty of layers to overlap and experiment and you should get pretty darn close.