Camouflage painting techniques?

I'm considering painting one of my older builds, an AE86, camouflage...
Anyone have any advice/tips/ideas on how to go about it? is it possible to come up with a decent effect?

What I would do is, paint the base colour first, then if you want a sharp looking camouflage, use masking tapes cut into shapes but if you want a blurred effects (not sure if this is the correct term), you can do the outline using pencil on top of the body, then using airbrush, follow the lines (you don't have to follow it precisely as it is a camouflage) and colour the insides, when it is done, clear coat the whole body. I think that should work. I use the technique when I build my Leopard 2A5 tank (except the clear coat part :iceslolan ).

You can spray randomly in different directions with different colors.

I've heard silly putty can be used as a mask for hard lines, but i've never tried it.