Go to a website that has information and photos of the planets, such as HubbleSite's Picture Album: Solar System (see Resources). Learn facts about the planets, including their average distance from the Sun.
Look at images of each planet, and notice how they have different colors on their surfaces, such as blue for the Earth, and red for Mars. Print out photos if you intend to mount them in your solar system art project, or use the images as reference material to help you draw or paint the planets.
Sketch in the placement of the planets on a large piece of poster board, starting with the Sun on the far left, followed by Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Farther out are bodies known as Pluto (formerly considered a planet) and the Kuiper Belt objects.
Cut out photos of the Sun and each planet, and glue them on the poster board in the positions you sketched. Alternatively, use paint, markers or crayons to color in the planets. Label each planet with its name. Include facts such as the planet's size and average distance from the Sun.
Go to a website that gives information about the relative sizes of the solar system's planets (see Resource, "Hands on Crafts for Kids: The Real Solar System").
Gather hard foam spheres of varying sizes, and paint the largest one yellow to serve as the Sun to make a 3-D solar system art project. Paint the rest of the spheres with a color scheme appropriate to each planet.
Attach a piece of string using a pin or tape to each sphere, and hang them from the ceiling in the correct order from the Sun. If you don't want to use spheres, you can cut out cardboard circles and color them and add labels, and hang them from the ceiling. Paint poster board black and then fleck it with dots of white paint to represent stars, and position this behind the planets to make them appear to be in space.
Add facts about each planet that you learn from your research, such as how long it takes to complete one orbit, or how many moons it has. Write this information on small cards that you attach to the strings or to the planet models.