picture shapes - what an amazing idea, i would have never thought of that! [actually this is not "picture shapes" it's how to make shaped bokeh but still a good technique of attaching the paper to the lens]
Fourth of July Crafts for Kids: Flour Lawn Stars. Cut out star stencil, sprinkle grass with water (to make the flour stick) and then sprinkle with flour. This idea also works for Canada's July Birthday. Just substitute the star for a Maple Leaf.