Most vampires are very ethical about what they do. This is not true of everyone, nor is it true of all people in all cases. However, most are good people that try to be of service, in some fashion, to others while working to meet their energy needs, feeding when needed, usually through a Donor or other non-intrusive means.
However, there are some occasions when people may need to protect themselves from being fed upon. These situations occur when the Vampire is frequently either unaware of what they are doing (unconscious psychic vampires) or in very rare cases when it is an individual that is not concerned about others. These types of people exist within every community and the Vampire Community is no exception.
There are a few techniques you can use to protect yourself:
1. Develop control over your chakra system. The chakras can be visualized as "wheels". Once you know this, you can, whenever you feel you are being fed off of without your consent, simply close the chakras from which the energy is being pulled. One way to accomplish this is by visualizing an iris over the chakra and seeing it close, covering it, with the intention to prevent any energy from leaving your body through that chakra.
2. If you become aware of the energy flowing out of you, you can, through the force of your will, simply pull back on it. It then becomes a battle of wills between you and the Vampire.
3. Most forms of spiritual cleansing will also help rejuvenate you. These techniques can include Smudging with incense (some of the best ones are Frankincense and Myrrh, Sage, Sandalwood and Dragons Blood. Spiritual Purification Baths can be used. If you know how to make Holy Water, you can bathe in that.
4. Finally, another technique you can use, whenever you feel your energy being pulled on without your consent, is to bring to mind any pain, whether emotional or physical. Most Vampires take the surface energies first, so by calling this to mind, you are basically turning their attempt to feed from you into a personal healing. Most conscious vampires know how to filter any incoming energy or transmute it. So, they are not usually susceptible to this technique. However, those that are either not conscious of what they are doing or are new to Vampirism, will usually not know how to filter the energy. So they will wind up with whatever pain you pulled to the surface of your energy and mind. Those that do know how to get around this technique also know enough not to try to take energy from people in ways that could harm them.