This spell is simple really.
First get a photo or drawing, or a seal representing the target of the spell then take this photo to a tree or a piece of wood.
Now summon up all your anger and or hatred for this person, until you've conjured up all the emotion you can, and focus that energy on the person in the picture.
Now, with all that emotion of hatred summoned up and focused on the target, drive a nail into the tree/wood through the picture's head. Hammer the nail all the way in the wood/tree.
If posible, come back later and summon up all that hatred/emotion again and hit the nail on the head again.
Repeat a few times later on.
Soon the target of the spell should start having bad headaches/migrains. If you want to stop the spell, take the nail out of the tree/wood.