Tacky costume jewellery suddenly becomes cool when you make it yourself.
Step 1: Sources for Materials
Small crystals (lead glass) or plastic "rhinestones" with flat backs can be purchased at craft stores. These are 2mm in diameter - I discovered later that I shoud have gotten bigger crystals, or smaller magnets in order for them to cover the magnets completely, but the earrings look all right as is. The magnets are neodymium discs 1/8" diameter by 1/32" thickness (3.2mm by 0.8mm), from kjmagnetics.com - very cheap, $2.00 for 25. Superglue...buy anywhere for under a dollar.
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
Don't separate the magnets, as it's easier to hold them in a "bar" than to handle them individually. Place a small drop of superglue on one of the ends. Be sure that it doesn't flow down in between the top magnet and the next.
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
Earrings stuck onto a pair of metal tweezers are pictured here. The backings are simply another magnet.
Step 4: Frighten Your Parents
To put on an earring, hold the magnet with the gem in place and then loosely apply the plain magnet to the other side of the relevant piece of anatomy. They are strong enough that it should spring out of your fingers and stick in place with the correct polarity - if you hold the plain magnet in place first, the front one might end up facing the wrong way around.
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.)