New age is one of those broad, sweeping labels that somehow fails to give any new information when used as an adjective - such as new age music, new age therapy, and so on. The phrase initially referred to a new age of man where human consciousness would be raised and people would evolve beyond materialistic preoccupations to seek spiritual enlightenment. Of course, muddying this utopian vision is the fact that if you're honestly looking for the path to enlightenment there is no shortage of those willing to sell you their roadmap.
The subject matter that can be placed under the new age heading is vast. A short list could include such things as aromatherapy, astrology, dream interpretation, drumming, channelling, chiropractors, crystals, feng shui, hypnotherapy, lucid dreaming, meditation, mysticism, out-of-body experiences, past lives, reiki, reincarnation, and tarot. Additionally, any religion a Westerner engages in that is not part of the three main religions - Judaism, Christianity, and Islam, but instead chooses something else, such as Paganism, could be considered to be new age. It is often unwise to call a pagan 'new age', though, for they can object quite strongly.
Regardless of how you feel about the range of new age subject matter, it is probable you'll find at least one thing you consider to be absolute foolishness; which is the basic problem with new age. When people hear 'new age' they are more likely to think of daily horoscopes and magnets in the shoes than the actual clinical value of meditation in stress reduction.
The stigma of fringe weirdness that new age has acquired accounts for its current lack of favour as a descriptive of choice. Of course, the subject matter that can be called new age remains with us, often categorising itself as an 'alternative' to something more socially acceptable.