Keep decorations simple for a more adult zombie birthday party. We did green or purple lights, "freaky fabric" (found at Walmart) and only one birthday sign strung across the main mirror - lettering in black and silver. Bloody canvases laying around, black torn table cloths and only one green skull with plenty of black light bulbs finished the look. One room had a bloody wall backdrop for photos and some rooms had cardboard "wood planks" across the windows.