What you need:
1. Pyrolytic Graphite tiles 50 mm x 50 mm is the minimum surface needed
2. Tiny Neodymium Magnets
3. A Big Magnet
4. A Rig that allows you to adjust the height of the Big Magnet
5. Straw to make the tiny magnets spin with air stream
Pyrolytic graphite is the strongest diamagnetic material known to man which means there is a weak repulsion force between magnetic fields and pyrolytic graphite. By adjusting the big magnet on a specific height ( by trial and error) the magnet can be levitated over pyrolytic graphite. When more magnets are added over the pyrolytic graphite tile they are both attracted by the big magnet above and repelled by their own magnetic fields which keeps them separate.
Step 1: Adjust the Height of the Big Magnet to the Right Level
Big ferrite ring magnets do the deed nicely. They are hanging on a threaded rod and thereby the height can be adjusted. This is one of the easiest ways to adjust the height and gives the needed fine precision.
Step 2: Add More Magnets and Blow Through the Straw
Once you have managed to get one tiny magnet to levitate You can start
carefully adding more. Finally gently blow through the straw to make them circle each other.