Found a collection of stock textures on the net that would be the building blocks for the image. Found a wall texture and smoke/ ink in water shot.
Dug out stock images of a broken egg shell and a jelly fish. These would be part of the visual elements to be used.
Picked out an expressive face from T-gar's stock collection on deviantart.com to create the 'protagonist' of the piece. Arranged the model's face on top of the texture and erased out enough to force a seamless blend. Colour-toning the image helped in setting the mood. The green was chosen to give it a little 'creep' factor.
Time to explode the face. Chopped off the eggshell and placed it to fit the contours of the face.
Added some shading and colour to get the depth. Air-brushing helped to get the desired effect.
Blended in some cracked earth/ peeling paint textures for stress marks where the face exploded.
Took the smoke/ ink pic and masked it out to get the 'hot smoke' feel. Blended it in Screen mode to get the desired effect.
Took a couple of the jellyfish pics, inverted, huerotated and curve-adjusted the jelly out of them till they looked adequately ominous.
Took another one of T-Gar's lovely face shots and placed them in line with the flow of the jellyfish body.
Masked out the extra bits and did the usual blend-mode/ colour correction routine till it started looking natural.
Did this for multiple jellyfish till a swarm was created.
Placed it all together. The finished piece started taking shape a little.
Added appropriate shading to get depth. Some ink-splats and similar textures were added to enhance the 'creep' factor. A liquid spurt on the head, some spot colour and final colour-toning signed it off.
Got the final image.