Originally Posted by Dak Drexl
I'm using Gimp, but I didn't make the textures myself. Just found 'em.
Edit: Don't let that dissuade you. Please tell
Usage of Photoshop's Cloud filter (black and white foreground/background color) followed by the threshold option and several other selection modifiers allows for the creation of shapes that are easily considered good camo 'blotches'. And since the Cloud filter is indefinitely fractal, many different types of shapes can be conjured up!
For smaller 'blotches' though, usage of the Cloud filter followed by the Sponge filter with all parameters set to "Max" can turn a sky-cloud mass into an instant camo, only with less contrast than the former option. You can experiment the combination of both techniques to create very eye-appealing camo patterns.
Using the Offset filter in the process can make the textures perfectly seamless. If you ever stumble upon someone who uses Photoshop, do give it a shot!
Example of the 'big' camo
Example of the 'small' camo