Vampires and werewolves have a lot of associated legends and mythologies. In fact, in some places the name for the two things used to be the same. This is not as odd as it sounds as one of the best ways to become a vampire is to start out being a werewolf. Wait, what? No, seriously. According to many legends, if you die as a werewolf (which can be more difficult than it sounds, since it's relatively easy (in some legends) to change someone back to human (sometimes accomplished just by saying the person's name (see the post))) and are not disposed of properly, you will come back as an undead that needs blood to survive, so a vampire. However, you would retain your ability to change into a wolf, which is related to so many of the legends dealing with the associations between wolves and vampires.
Interestingly enough, all of the vampire legends begin with blood-drinking demons. These go back thousands of years, and, sorry, but I don't think there's anything you can do to become a demon. The earliest vampire legends, which don't even go back 1000 years, all have to do with demonic possession, usually after you were dead. For instance, if you had a wound that was not cleansed with boiling water and you died, you could come back as a vampire. In fact, for a while, people thought just about anything could cause your corpse to become possessed by a blood-drinking demonic spirit and come back and ravage the local village. Corpses were often buried face down because of this. That way, when they tried to dig to the surface, they'd go the wrong way. Crafty, huh?
And, as an aside, many (unrelated) cultures believed these undead had a thing for counting. The Chinese would bury the dead with a bag of rice so that when the vampire awoke, it would compulsively count the grains before attempting to rise. Other cultures used sand. That whole Count von Count thing?
Anyway...
Most of our modern views of vampires didn't come about until the 19th century. And most of those grew out of one book: Dracula by Bram Stoker.
The sustained feeding idea has also given rise to the idea of it being a pathology. A disease that you catch. So we have three basic views on vampirism: spiritual, mystical, and physical, which give rise to different variations on how to become a vampire based upon which view you hold.
In short, you have three options:
1. You have no control. Your dead body becomes possessed by a blood-sucking demon. Possibly, you can help that to happen by having uncleaned wounds that you die of, but it's no guarantee.
2. You have some control. Become a werewolf. Try to make sure that you die while still a werewolf and hope that no one disposes of your body in a way as to keep you from returning as the undead.
3. You might have some control. First, you have to meet a vampire. This could be difficult as they don't go around handing out business cards. If you find a vampire, convince him/her to turn you into one, too. Mostly, this is going to involve the vampire biting you. You will just have to trust the vampire to do whatever needs to be done to make you into one.
Also, you could learn the special math formula from Briane Pagel's excellent novelette, "Augurs of Distant Shadow," currently found exclusively in "Shadow Spinner: Collection 2: The Man with No Eyes (Parts 6 - 12)."
