These are pretty inexpensive to make, and you can put them together in about half an hour if you've made jewelry before. But be warned, it's kind of a loosey goosey process, so you might need to try a few different configurations until you're happy--the final product for this Instructable were my third try!
Step 1: Supplies
Here's what you'll need:
Watch gears (try Ebay--I got a little tin of about 50 gears for $12)
Earring hardware: ear wires, posts, jump rings
Tools: assorted jewelry pliers, wire clips
Step 2: Start your post
Bend a ring onto the end of your post and attach your first gear.
Easiest way to bend a ring: about 1/4" from the end of your post, bend the wire into a right angle. Then use round pliers to grasp the end of the wire and bend it back into a ring.
Step 3: Add gears
Keep adding gears, hands and other bits. I did this by bending the post into more rings and adding each bit, then tightening the ring. Experiment to see what you think looks best.
You can also thread watch bits onto the post by using jump rings (or creating jump rings by bending a ring from a wire post and clipping it off).
Step 4: Attach to ear wire
When you're done adding gears, bend a final ring into the post as an attachment point. Then take your ear wire, bend it open, and slip the post onto the ear wire. Close and tighten.