Or using other natural textured things for decoration like sand or bark. In chill spaces, fluro pencils, crayons and pens and big sheets of paper often go down a treat. Invigorate with lotsa smells - incense and oil burners. If you're allowed, candles look fantastic. As do unusual lamps.
Broken mirrors are another great material for making freaky collages on walls.
I suggest encouraging party-goers to bring various items to contribute to the gathering. It's always exciting to see what people turn up with. They had real branches wit leaves, and little paths between them. Twist together with pliers. The paper can be any colour.