I first used a Krylon kit that had 4 flat colors in it and a plastic sheet with cut outs of leaves, twigs, etc.
It has OD green, a dark brown, a sand color and black.
I spray the outside (of an AR) off with brake cleaner a couple times. Then wipe it with a lint free cloth and rubbing alcohol a couple times. Let it dry and paint.
I've used the stencil sheet in the krylon kit.
I've used painter's tape (torn into ragged strips).
I've used a combination of nylon rope and wires of different diameters.
The previous 3 sentences describe what I used, with the paints, to get random break up patterns in the colors.
Pick your base coat/color. One or two light coats. Apply the material you'll use to get the pattern you want. Apply the next color. One or two light coats. The more colors, the more you need to think about what you use for the pattern and how to get it on/off the rifle. You can try it on some cardboard first to try different techniques/materials to see what you like the best.
painter's tape
rope/wire
krylon kit stencil
