In 2011 my family moved to a new house. It was our first big move as a family, and days afterwards my baby had his first birthday. It was a tumultuous time with a new job, new house, unpacking, no nearby family or friends. It took a couple of months to unpack and by the time I did, I had a hefty supply of large cardboard boxes taking up an entire room of my house and the calendar had just ticked over to October. Instead of getting rid of the boxes, I decided to recycle them into Halloween Decor. All it took was some black paint, tissue paper, and a trusty box cutter. My new house was uniquely suited to monster silhouettes because of all of the windows in the front. I made a different one for each window, and taped them in place with duct tape.
A friend of mine shared the photo and moving box story with this website I hadn't heard of at the time -- "Reddit". And from there it went a little bit viral. Every year since I've seen it re-shared and re-posted across the interwebs.
Unfortunately cardboard moving boxes don't hold up over time. We only lived in that house for 2 years. When we moved we didn't take the old cardboard decorations with us. In our new home, I decided to re-create the experiment but in a more permanently reusable medium: Wood.
Now set-up each year is easy and our home immediately becomes a Monster Sanctuary each Halloween season. Take-down is also easy, and they store away flat!