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.
Photo Booth for reception - LOVE! We used a red round frame for reception photos at a wedding here at our farm. the photographer edited for black and white photos with only the red frame in color. Definitely worth a try.