we're looking to create a blood-cells sort of effect, like this:
EDIT: sorry, i went over my bandwidth limit :'& so i've posted the details of filters in text.
EDIT: thx to truer i've got the images hosted
now here's how:
1: create a new document of any size, and make the background black.
2: go to Filter > Noise > Add Noise and use about 50%, monochromatic Gaussian noise
3: next go to Filter > Artistic > Cutout, and use settings like:
and you should get something like:
4: now we start getting our "blood cell" look. go to Filter > Stylize > Glowing Edges and use these settings:
and something like this should come out:
5: image > adjustments > hue/saturation and use settings such as:
...and there you go, a simple blood cell effect! you could add a light clouds layer set to Multiply to get some more depth into your image, but that's another story.
PS: if you want a gap in your bloodcells without having either a cut-in-two bloodcell or spend ages doing a polygon marquee, grab your selection in the "cutout" phase, and make it a dark gray. you should then be able to complete the steps without blowing a blood vessel
-- Bubbinska