Divide the icing in half. Knead the peppermint essence and blue food colour in to one half, in drips, until you have a flavour and colour you like. Repeat with the rosewater and pink colouring in the other half.
Roll the two icings out on a lightly sugar-dusted surface to around ½ cm thick. Use a small biscuit cutter to stamp out shapes – we used hearts and stars in two sizes, then re-roll trimmings to get as many shapes as you can. If you want to use as decorations, stamp a hole out of the centre using the tip of a small piping nozzle or poking with the end of a skewer. Dry on a sheet of baking parchment for a couple of days. Store in airtight containers, layered between more sheets of baking parchment.
To make decorations or napkin rings, thread some ribbon through the holes and tie around a rolled up napkin, or to the tree.