Cut the aluminum into any shape you like. Sharp scissors cut easily through the thin metal. Get creative -- cut out stars, circles or more complex patterns.
Sand down the cut edges. Without a good sanding, these edges can be dangerously sharp.
Unless you want the colors and designs the aluminum already has, sand down any area you want to paint. The aluminum has to be roughed up or paint won't stick to the surface.
Paint the aluminum. Acrylic paint works fine and can withstand the weather.
Once the paint is dried, display your new creation. Hang it up or stick it in the ground. Aluminum makes great recycled Christmas tree decorations.