Empathy

Empathy is an ESP ability that is centered around emotion, whether it be yours or someone else's. Empathy is a common ability which in one of its most basic forms (experiencing the emotions of another) often doesn't require practice should the user have been born with it as most are. Users that practice this ability may be able feel another person's emotions as well as manipulate them with enough training. It can take months to become very proficient in this ability (as with any other ability). This ability can be applied in a multitude of ways that you might not have thought of before. Like most other abilities, Empathy may come easier to some than others.

Empathetic Meditation
Start out in a comfortable position (either lying flat on your back, or siting cross-legged) and close your eyes. Clear your mind and try to feel the collective of all your emotions at once (in rotation, like happy then sad, etc.) This helps you get a better grasp on your own emotions to help you tell them apart from other's emotions.

Feeling The Emotions Of Others
As a beginner, it helps to meditate before attempting to feel another's emotion (as you get more proficient, meditating beforehand is not necessary). Find a willing partner, with whom you can practice. Instruct them to reflect on a time that draws a powerful emotion (the emotion itself doesn't matter as long as they don't tell you). You may close your eyes, or keep them open but you must begin to open yourself to the resonance of your partner's emotion. When you feel their emotion, it will feel like your own.