Spread the old newspapers out in an well ventilated space. You should have enough paper to cover a space twice as large as the poster-board you will use. If you plan to paint inside, it is important to have windows open. A fan pointed out the window can help remove the paint fumes.
Place the poster board on the newspapers.
Compress one section of newspaper into a loose ball and set it aside.
Pick up the can of green spray paint and the can of yellow spray paint, one in each hand. Spray them together creating a circle of paint slightly larger than your largest jar lid. While the paint is still wet, take the ball of newspaper and mash it into the wet paint several times.
Repeat step 4 in two other spots on the poster board using red and yellow in one spot and red and green in the other spot. Allow all the paint to dry before continuing with step 6.
Place your three jar lids over the spots you applied paint in steps 4 and 5.
Pick up the can of black spray paint and the can of blue spray paint, one can in each hand. Spray with both hands simultaneously, moving your hands in small circles with the two colors of paint overlapping. Don't attempt a smooth even color. Create patches of lighter blue, darker blue and black. Cover all of the poster-board with paint, completely covering the paint from earlier steps.
Take the can of white spray paint and lightly press the cap causing paint to drip and spray irregularly. This will allow you to create a star-like splatter over the painting.
Remove the jar lids and admire your first spray art painting!