I am super happy on how my Frankenstein turned out. I used the same steps for my tombstone project but went with green paint instead and then drew an adorable monster face with a black marker.
Get an empty box and cover it with craft or packaging paper.
Then paint your box green or whatever color you want for your desired monster.
When your done doodle on a face and that's it. I also made a ghost/mummy box. I can't decide which it looks like but all I did was take a big long empty box and wrap it with white streamers, I was originally thinking mummy but it looks really ghostly.