Cut out a large number of colourful bell-shaped pieces from old Christmas cards ( or anywhere, but Christmas cards seems appropriate ), all the same size - about 8cm high - and shape.
Fold them in half, vertically, to an angle of 120°, with the pretty side inside; then glue them together in threes to make "bells".
The Christmas card bells first appeared on our tree in the Carol service, 2008, and stayed there for the Christingle service, 2008. They'll probably turn up again some day, but unless they play a significant part in the service they might not be mentioned.
We used just the same method with heart shapes to make decorative hearts for the Christmas services in 2009.