Smoking Skull

Had an experimental session today with the smoke photography,
I took a series of photos of the smoke rising from an incense stick and was hoping that i could see some recognizable shapes from within the smoke with the idea that I would colourise the smoke from a few frames and mix them together, however after 30 mins in photoshop it was apparent that it was a lot harder to get the smoke to look like any recognizable shape, so back to the drawing board and I started layering 10 of the images on top of each other with the smoke only on the screen and set blending mode to screen, this deleted any black in the layer and before i knew it, there was a skull forming within the smoke.
I obviously need to have a few more practices with this technique , but i'm generally pleased with the first attempt.