Let's see, how about:
1. Creating a word cloud or image cloud reflecting each individual in class.
2. Put together a huge collage made out of all sorts with a school theme or term theme.
3. Get hold of some felt and do a class felting project - make a wall hanging or several smaller pieces.
4. Create a mini garden in your own self made wooden boxes.
5. Make paper - out of recycled old paper that is print and toxic chemical free!
6. Get some modelling clay and get each member to make a pot or a bowl or a sculpture.
7. Plant trees, sow seeds, create wildflower patch.
8. Make an ideas box out of cardboard/wood/papier mache.
9. Make sock or glove puppets and put on a mini drama.
10. Create huge paintings on a wall and choose a theme to go with festival/special date/celebration.
I hope you get something nice done even if you don't choose one of these! Bon Voyage.