Two other things that you can try that i have used is. Find some netting used as scale panting (netting) material then lay it flat on a peace of wax paper(this will help it release latter). get some silicone, I use the auto stuff thats used for gaskets. Paint it on the netting with a brush leaving what you want painted uncovered and leaving a few random dots open for the paint to pass threw. Let it dry and remove from the wax paper then clean the wax off with alcohol so the wax will not mess with your paint. clamp it on and spray two colors that are close to each other to make it more life like.
The second is take your milk carton or paper and put it on a peace of foam. Start punching holes with a couple things. Nails, pins, knife or any thing you can think of and use that as a stencil.
I have used riped paper and liked it. but so simple I have not used riped tape used tape but not ripped tape so simple I walked right past it.