I would use royal icing and then decorate that with silver balls. Fondant icing is a good alternative if you want to avoid faffing about with piping icing. Just use the same cutter as for your biscuits.
I have made a batch of lovely snowflake cookies for the school fair on Friday, they need decoration though. I'm thinking of desiccated coconut but what's the easiest way to get it to stick? I have tried icing pens before but they looked a bit crap frankly, or maybe I could dip in white chocolate - does anyone know if it melts like ordinary chocolate?