Bram's Vampire Hunting Handbook
Chapter 5 - Vampire magic I
As stated in early chapters, vampires are far more adept at magic than common humans (and even most fairies). While their biology is basically human, their magical powers make them incredible tough.
Humans have to study a lot to learn how to harness their inherent magic, since what little they have are in their blood. Magic users have to learn to be aware of this magic flow (which is, in itself, a challenge), and then how to control it. After that, they can learn how to project that magic to the outside of their bodies. Without going too deep on the specifics, we can say that you do magic by saturating something with your particular magic energy, in order to make that thing temporarily a part of your own body, thus controllable by your soul. As simple as it might sound, you need a deep working knowledge of nature to learn where to direct magic in order to achieve your goals more easily.