These are kind of uncontrollable but:
First make an image of almost equal proportions something like
500 x 300 or similar if you're making a Sig. then you go
Filter>render>clouds
Filter>render>difference clouds
Then hit Ctrl+F 4 times so that you have balanced clouds
Now, go to Ctrl+L and drag the black slider (on the top bar) to the left
Until you see something in relation to lightning
Now go Ctrl+U check the colorize box and pick your color
Whala, instantaneous clouds :D |