Paint black card stock (need heavy paper for water colour) using blue and white watercolour paint. This will be the background for your paper snowflake.
Set backgrounds aside to dry.
While the paint is drying, make paper snowflakes. Fold a square piece of paper diagonally 3 times and cut off the uneven end. Design flake as desired. (Allow kids to create many, it will take a few tries to perfect their technique)
Let them choose their favourites (any more than 3 hides the background) Glue them onto your dried background.
(Optional) With a toothbrush splatter watercolour paint over the whole project for a snowy look!