The thing about the esoteric practices - they are NOT this New-Agey thing that Beliefnet's categories make them out to be. They are powerful and potentially dangerous. that is why they are what they are. They are hidden because they have such potential to destroy the practitioner. That is why you never learn them outside of a master-disciple system. Without the proper guidance, the student would do themselves more harm than good. Indeed, they could easily destroy themselves. This is clear in esoteric forms of all the major religions. What are the esoteric traditions?

Sufism

Eastern Orthodox Chrisitianity

Shingon and Tendai Buddhism (also Tibetan)

Some forms of Taoism

Kabbalah (to a large degree)

Much of Hinduism

To some degree Wicca. But Wicca not not as concretely esoteric.

The characteristics of all the esoteric traditions are:

a specified training and level of understanding is required before one can begin to practice

a master-disciple relationship is required for training

the teachings are not able to be shared outside the tradition

the requirement that in order to validate the training, a mystical (that it, direct experience of the dultimate ground of reality) event must occur. This is often an empowerment or "grace" experience

There must be an initiation of some form