Sometimes I think that “New Age” is a synonym for “things I don’t like/agree with”.
I have a particular interest in this topic because a lot of people confuse New Age with Paganism (while the two traditions have some overlap, the two movements have different origins, literature, Paganism is generally polytheistic while New Agers are generally monistic or monotheistic).
I took a few courses of study in (secular) university where we discussed the New Age in depth. I personally divide the movement into “Eastern” and “Western” camps.
In my opinion, these are some beliefs and practices that are thought of as “New Age”:
Eastern: some forms of yoga, chakra meditations (especially those that only use seven chakras, one lady who gave a talk revealed an unknown “eighth chakra” called the “Star-Soul chakra” which, as far as I know, isn’t in any Hindu texts), “tantric” sex (especially when it’s all about the sex), the (over) use of the term “Namaste”
Western: crystals, channeling, psychics, spirit guides, Ascended Masters, “angel therapy”, flower essences, orgone energy, Atlantis and Lemuria, almost anything that’s marketed as “genuine Native American X” by non-Natives or fake Natives, Sedona, Arizona is a hotbed for this sort of activity
These are some of the terms I’ve noticed that crop up in the literature (I went through a New Age phase at one point): vibrations (including things like “vibrational medicine”), the concept that some souls are “more evolved” than others, ego-centric phrasing (ie. the ego is holding you back from reaching your full potential), indigo, crystal, and rainbow children. Ironically, much of the literature is very anti-materialist when New Age kitsch tends to cost a lot of money. There’s actually a joke about that:
“What’s the difference between a Wiccan and a New Ager?”
A decimal point. (Wiccans don’t usually charge for their services, or usually offer them for a cheaper price than a New Age guru would).
Also note that non-New Agers might also engage in some of these practices (yoga was originally an “import” from Hinduism, and lots of Pagans like crystals). I would say that the difference is in the language used and the context of the belief/practice.