The first step is to find some guitar picks that really catch your eye. Any music or guitar store will have them, and they'll most likely be standard looking picks (colored with a Fender label). The ones shown in the picture are decorative picks from Austin's own Wild About Music, located on E. 6th Street.
Next you need to put a hole in the pick. Guitar picks come in different thicknesses. If you get a thin or extra thin pick, you can probably poke a hole in it with a bead reamer. Personally, I like the weight of medium to thick guitar picks. They still make very light earrings, but I think they have a nicer swing. It's entirely up to you!
If you go with a medium or thicker pick, you'll want to use an electric drill with a very small bit. Probably no larger than 1/16. Remember to protect your eyes when drilling. Safety first!
Mark each pick with a Sharpie where you want to drill. The placement of the hole should be close to the top. If you drill too far towards the center of the pick, you'll have a much harder time attaching your pick to anything.
Also, keep in mind that when you drill through the pick, you'll also drill through whatever is directly below your pick. Get a stack of old magazines, and use a hand clamp like the one shown in the picture to hold the pick steady on your drilling surface.
I used an old edition of Vogue, and I positioned it on a table with a ledge so that I could clamp the pick, the magazine, and the table together all at once. Position the drill directly over the hole you marked, and gently press through the pick. You should get a pretty clean hole, but check the back side for any rough edges that might require filing.
Now that the hard part is over, it's time to let your creativity run wild! You can use jump rings to attach chain for added dangle, or go simple and hang them directly from an earwire. You could even drill a hole in the bottom of the pick to dangle beads! Guitar picks are pretty inexpensive, so you can try lots of different looks!