It's not magic, it's Magnetism! The younger students are amazed when they make the magnets "float". When I ask them why this is happening they answer, "The magnets are N and N and S and S!" Then I know the "boy -girl" cardboard magnet activity sunk in! :)
To help show the invisible Magnetic field of different shaped magnets, I make a "bear" (our school's mascot) using an overhead projector and a clear viewer containing oil and iron filings. I use a ring magnet for the eyes, a cylindrical magnet for the nose, a cow magnet for the mouth and a rectangular ceramic magnet for the ears. See next photo
This is the layout of magnets I use for the Magnetic field bear. Of course, the magnets are set up under the viewer when I do the demonstration. The viewer contains a clear plastic rod to disperse the filings between demonstrations.