We can feed in many ways by touch; however, this normally tends to draw attention to who and what we are. Any place on your body that forms a hollow (like the hollow in the base of your throat, or in your shoulder, or palm and females have an extra "hollow" that men don't have *smiles*) can be used to feed from. We can also drain someone when they touch us and we don't wish to be touched.
To feed by touch can be done in self-defense, casual contact like a handshake, or even during sex.
To feed by touch we tend to use our right hand and drain with our palm (NEVER put your palm over their heart when feeding because the shock could seriously hurt the donor and even kill them if they have a heart condition), this is the reason we don't like to shake hands.
If we are attracted to someone we will feed with our mouths, either from their shoulder or from their necks. We tend to be easily aroused if someone nuzzles our necks because of this. We do not drink their blood but we do drink their energy, it is similar to giving a hickey (could be where giving hickeys came from*winks*) and this is the most intimate we psi-vampires get without actually having sex.
Some female psi-vampires feed from the hollow nature gave them during sex and letting the man just assumes that they are now tired do to the exertions of having sex (this can be addicting to the man though).
When we are attacked or grabbed by someone in a threatening manner we tend to grab their arm or hand with our hand or hands and drain them reflexively or instinctively. Many of us don't even realize that we are doing this (especially if we are in the process of awakening), we just assume that the attacker got tired of fighting us.
Some of us psi-vampires will feed from you by touch if you have angered us, and only enough to tire you and get over our anger.
If you have greatly angered someone and they then walk up to you and put their hand on your shoulder while talking to you in a quiet even voice, and you start to feel detached and tired then you are more then likely being feed from and they are trying to mesmerize you with their abilities so you won't notice what they are doing. One of the ways of recognizing a psi-vampire.