Take your aibrushing tool, lots of edible colours, artist's sponge tool and feather up our cake!
This is a very effective way on how to create a feather pattern on your fondant.
Use the softest airbrushing setting and after each spray work straight away with a slightly damp sponge. Start with a less damp sponge (too damp would create a mess) and gently brush away into the colour with sharp edge of the sponge until you achieve your desired feather look.
Add more colour if required and repeat the process. Careful not to overdo it as you would end up with a clump of wet colour losing the soft look.