doing an Ice Age cake and using a non-crusting icing. Smooth it looks nothing like snow. But I don't want it to look like I can't make it smooth and just iced it any old way. It's for a little boy, I have white glitter, but it would be hard to get on the side of the cake. Any ideas/examples??

Chopped coconut shreds?

Use half and half granulated and icing sugar, mix in a small bowl and sprinkle thickly on the top. Let it fall over onto the sides. You can't make the whole side look like ice because the "powder" won't obey the laws of gravity...