Dinosaur week: Fun & Simple dinosaur activity for kids! Maybe for older kids give each shape a numerical value and have them add how much their dino is worth. Can use with class to compare/contrast amounts, etc.
My advent calendar consists of 24 little houses made out of paper. They can be easily folded flat for storage. Could be an easy way to create an elaborate Christmas village that is easy to store but looks fantastic and festive.
Pre-make paper mache bracelets and let the kids paint and decorate them. Then spend a week where they can give the bracelet to someone who is sad or having a tough day or to someone they have not talked to before.