Heres how I'm doing British Night Camouflage on a model.
I did use an airbrush, but cans would have been fine. The method is to draw the camouflage pattern full sized on paper. Then cut and tape them on. RAF is perfect because the camouflage is sort of soft edged ( 1/2"), and if you let the edge of the paper float a tiny bit, and control the angle of the spray, it makes a nice effect. More than scale for sure, but I like it.