Learn how to create an abstract smoke effect from scratch.
Open up a new document, any size is fine (I used 500×500px). Fill the Background White.
Go Filter -> Liquify and mess with it till you get a nice smoke effect going. (Note: I use the default Liquify settings, brush size 100.)
Create a new layer and repeat the process, this time using a dark gray.
Repeat the process a few more times, each time using a different shade of gray.