Round holes yield long, thin strips of lemon rind, perfect for garnishing soups or desserts such as cheesecake or ice cream
tiny blades yield finely grated bits that distribute lemon flavor throughout; good for baking or salad dressing
U-shaped blade yields long, curling strips. These curls can be used for decoration on top of cupcakes, or cakes.
Whatever you do, don't throw away the lemon peel. Yes, I am completely guilty of doing this. I will take a lemon, cut it in half, get the juice out, and peel goes straight to the trash. Not anymore I won't. I will make sure I put those peels to good use and make sure I use the whole lemon.