You can do this DIY-project at jome, or at the museum with your school-class.
Take a photograph - it's extra fun to make a decoration with a selfie!
Fold the photograph in half
Fold back and crease one edge about one cm...
...then fold the other edge to match.
Unfold so you are left with a crease.
Cut 1/2 cm strips, cut up to the crease you just created.
Do this all along the photograph.
Fold the piece of paper so that the image is now facing inside-out.
Re-crease the folds.
Join one end to the other using sticky tape. Fan out.
Attach a string tou your decoration, and it is ready for the Christmas tree!
The idea is taken from The Photographers Gallery, London.