You can use the plastic netting that some produce like onions come in as a stencil. Paint your prop a dark color, wrap the netting tightly around it, then spray paint or airbrush over it in the color/design you want. Once removed the netting will leave a diamond shaped scale like pattern behind.
For wings a stretchy nylon or spandex style fabric with a pre-printed pattern would be great. I'm sure a fabric store would have a ton of different patterns in this fabric type. Someone is making it as I see folks wearing similar patterns in yoga pants all over the place.