First had one head, that I drawed/resized really well.
Photo filters, added color noise, posterize effect, Levels (increase dark output level slider etc.), really soft brush around the edges help a lot.
Then do a lot of copies of this pic, and drop one on top of each layer, each time nudge/resize it a bit more.
This can be done pretty fast.
...or if the movement is more complex, do this:
original head -> make copy -> move/resize/apply on next layer -> make copy of this new head -> move/resize/apply on next layer... so the movement is smooth
This obviously takes a bit more time but looks a lot better.
yeah, i figured you must have made multiple copies of the same head on different layers. when you apply to next layer, do you do that manually or is there a short cut for that?