Lots of people have different techniques. Let me know which you use or if you have some other advice. The following is in no particular order :-)
Some people swear that you should put the chocolate in the freezer for about 10 minutes before you use any of the following techniques. Others say to melt the chocolate in a pan and then refrigerator but soften slightly before working with it. So here are 8 different tips!
1. Grating: Cut chocolate into a chunk that fits comfortably in your hand. Grate the chocolate using a microplane grater, handheld grater, or the smallest holes on a box grater.
2. Curls: use a cheese slicer. Depending on what type of curls you want--thick or then.. depends on pressure you use.
3. I've been known to use a vegetable peeler.
4. And, I've also used a drum grater (Mouli Grater). Friction doesn't melt the chocolate, and there's no heat from your hands.
5. And here's a good way to make Chocolate Curls with softer chocolate: Let milk chocolate or white baking bar come to room temperature, then carefully draw a vegetable peeler across the bar. For small curls, use the thin side of the chocolate piece; for large curls, use the broad surface.
6. More info on Chocolate Curls, especially if you're going to be making a lot of them. Take a block of chocolate-1 lb. (if you don't have one, melt chocolate and put in cake pan to harden. Run knife around edges to loosen and invert). Place on heavy or sturdy surface and use a clean cheese slicer.
7. An alternative would be to melt the chocolate and put it on a cooking sheet.. use spatula to spread. Put in refrigerator, and test that it's not too soft. Scrape the bottom of the pan with a metal spatula.. curls!
8. Once curls are made, I usually put them on parchment paper until ready to use.. and sometimes store them in the fridge or a cool area if I'm not ready.
Designs: Curls, Fans and other shapes.
And whatever you do, be sure and practice.