Step 1: Sources for Materials
Tools: A pair of tweezers or forceps for picking up the crystals (if you can find plastic ones, these would be better than metal), and a toothpick for repositioning.
Step 2: Attaching Decorations to Magnets
Pick up one of the crystals with the forceps and place it on the glue. You'll find that if your tweezers are made of metal, they will glom onto the stack of magnets, possibly causing you to drop the crystal, which is why plastic ones would be better. An alternative is to place a crystal facedown on a surface and then dab the glue-covered magnet onto it.
Since superglue sets very quickly (duh!), you have only a few seconds to reposition it by pushing it around with the toothpick. Allow the glue to dry for a few minutes.
Step 3: Earring Backs - Just Another Magnet
Step 4: Frighten Your Parents
Small magnets shouldn't exert enough force between them to cut off circulation; be warned that this might be a problem if you use larger, substantially stronger ones and wear them for a long time.
(Note: the only real piercing in these photos is the silver ring in my earlobe. I plan to give the magnetic ones to my un-pierced sisters. Although magnetic jewellery may be rather tacky, it could be a good way to try out a look before getting a real piercing.)