My DIY Pokemon party table covers. $1 store white plastic table cover, red plastic cover, black duct tape, and a paper plate. I folded the table covers in half, then taped them together with the duct tape. I put more duct tape around a paper plate to make the button, but they looked fine without the button also.
For castle theme classroom - castle doors are made from poster board covered with wood grain Contact Paper and black duct tape. The hinges are drawn on with permanent markers. And then I added paper chains and a lock because these doors are locked.