This is not as had as you may think, We'll first make some steam, so lets get started.
1. Open your image.
2. Make a new layer.
3. Get your rectangle marquee tool and use a feather of 15px.
Select an area where you want the steam.
4. Set you colors Foreground = 8f8f8f & background = ffffff
5. Now go to Filter > Render > Clouds
6. Filter > Blur > Motion Blur
7. Filter > Distort > Wave
8. Set the layer to Hard Light and change the opacity to 85%.
9. Duplicate the layer.
10. Edit > Transform > Flip Horizontal. Ctrl + D to deselect.
Now that's steam!
Final Image:
