Once your petals are dry you can put them all together in a basket or divide up into little pockets/envelopes – origami paper is a good choice for paper cups as its already cut down into little squares and comes in lovely bright patterns and colours.
Be warned however, should your petals get wet again once it has been dried, it has been known to bleed through paper or, heavens forbid, a wedding dress! Although this is only if the confetti is actually soggy.