go get 20 dollar press board from lowes or home depot.
make a box....spray paint it woods colors (flat colors)black/green/brown/yada yada.
and throw a bunch of brush on top of it and on the sides...make it about 3 feet tall.
make sure you cut some holes in it for a draft...but not too big. and watch out for wasps after you come back to get your buds...lol...they like those things for some reason.