I wouldn't suggest trying to feed off from others energies... there could be more to it than you initially think, especially if your not very experienced. You could gain their insecurities, depression, anger, bad thoughts/feelings, etc. On top of that most people choose those that they don't care for and dislike which makes things worse. Its my belief that people have different vibrations and if you absorb energy from someone that you dislike it could disrupt your vibrations or you could become more like them. You've heard the terms "I get a bad vibe from him/her"; "We get along great, like we are on the same wave" etc... there is definitely a solid truth to it. If your a sensitive or don't know how to protect yourself really well I would very strongly suggest you stay away from such practices. Just my humble opinion... I wish you well.