By its nature, Vampirism is no more different than energy work. A person takes in energy from their environment, processes it through their spiritual metabolism and excretes it, leading to a rejuvenated energy system in areas of high spiritual potency and sudden alerts in areas where the spiritual body calls for a warning. This can be seen as the basis of Spiritual Empaths, where their metabolism is much more sensitive and picks up on energetic debris more quickly than others, resulting in a warning response. For the energy vampire, this process is done with awareness, for various purposes related to healing, transformation and alchemy.
Vampirism and the Sexual Archetype
Most often, vampiric spirits are painted as closely tied to the life force. They often appear as young, beautiful women that seduce men and partake of their life force (represented by the blood). They can also take the form of animorphic creatures, such as the Empousai. Some vampires are credited with sudden sickness, misfortune and the loss of children, showing them as being intrinsically tied to the movement of the vital force of creatures, for bane or benefit. This is most found in the act of Sexual Vampirism, where the vampire partakes of the energy of their lover, often a donor, in order to strengthen themselves spiritually.
As of late, there has been much written on sex magic for the direction of forces. Most often, this is to cum up the spine, that being to direct the sexual energy raised up the Sushumna Nadi, associated with Lailita Tripura Sundari. A similar form is found in Dual Cultivation, where the two persons partaking in the sexual act strengthen the flow of generative energy (associated with Swadhisthana Chakra and the Lower Dantien) through the microcosmic orbit. The goal here is to take the energy from its dense form (pure sexual energy) and raise it up, slowly refining it and transforming it into Nectar (Blissful. Diamond-Like Awareness).
A less featured aspect of Vampirism is the ability to heal. From this, the metabolism is primed through constant acts of vampirism to receive 'dirty' energy and transform it into clean energy. The goal of the Vampire is to absorb energy into themselves, strengthening their own reserves as well as their metabolism to remove the debris of energy and allow for a purer, transcendent flow of energy. In this case, we are simply taking the negative energy that causes issues in the person's life and changing it into usable energy and giving it back to them.
This method is one I've found useful, though I have not been able to find a source for it. In this method, one uses the shadow body and causes it to coalesce around the person, becoming a cloak of shadow, with tentacles or hooks driving into their body so as to absorb the malign influences that are causing issues, taking it into the shadow bod and essentially 'digesting' it. They then channel on some force, such as the sun, or earth, and bring it back into the person. As nature abhors a vacuum, the person will have pockets of energy that demand to be filled after the vampirism. Thus, to fill these with appropriate forces are necessary.
Vampires have a bad rep in contemporary spirituality, seen as the source of bane and essential 'energy suckers'. This method does little to avert these but has been tested well enough through work. When preparing to go to sleep, focus on the person you want to devour from. Imagine the spiritual body rising up, leaving the body limp, and taking the form of some animal or spirit before riding on the Night Horse to the enemy's abode where they are, presumably, resting. When there, let the tendrils of shadow from your body pierce into their body, organs and centers of focus to devour from them, drawing their vital energy into themselves. A clear sign of this would be a sudden burst of energy in the body as well as the seeming fatigue of the enemy.
As a method to take away an enemy's ability to act, Sympathia is used. Fill a cup with water that has been stained red through some dye or wine, grape juice or pomegranate juice. Consecrate it as the enemy's life force, using the Hiss of Daphomey (a hssss sound) to channel their spirit force into the liquid before declaring that you are drinking of their essence, that they may not be able to act against you. Drink it fully. Alternatively, give it as an offering to the spirits to partake of it, thus partaking of the sacrifice of the enemy.
The Pact with the Empousai
Under the reign of Hekate are the Empousai, Lamiae and Strixes who appear as vampiric spirits in various forms. During the Deipnon, Hekate arises from the underworld to lead the train of the dead, an essential Wild Hunt, so as to resolve unfinished business. During this period, offerings may be given to the Vampiric Spirits of Hekate's Train, calling them to devour of the magician, providing their own force to fill them up and make them unto the image of the Vampire. Over time, a particular spirit may give their sigil and name which can be used in personal ritual.
One of the ethical areas of feeding are on ambient energy raised by crowds such as at concerts or busy spaces. This energy can be filtered through the body, and this can also be done in the home so as to act as a suckerfish, cleaning the aquarium walls of algae, in this case, metaphorical sludge. If not desired, a vampiric servitor can be made to this cause to devour anything that is in the space, allowing for better things to come in.