so far this term:
DD (reception) has needed - glitter, gold pen, glue, holiay brochures, coloured card, photos with the class teddy and pressed leaves for homework. jam jars, toilet roll tubes, an old shoe, baked bean tin, cake decorations, cereal box, family photos, a piece of oasis and stuff for harvest festival, a national costume, £2 for own clothes day, halloween costume, change for a cake sale and there will be a costume for the christmas play soon.
and my little brothers and sister (years 5 and 6) have needed - pipe cleaners, lolly sticks, cake cases, balloons, red t-shirt, ribbon, string, newspapers, masking tape, poster paints, wrapping paper, odd bits of change for various charities, lard, raisins, bird seed and netting.
So I would recommend a well stocked box of odds and ends of craft stuff, old clothes/sheets that you can cut up for costumes and a handful of change.