Hi,
I'm not sure there is a "method", although it was pretty obvious in the New Age'y days that they were simply on repeat mode and not really working small details to keep the music alive other than just some sonambolist crap, which so many "stores" sold as healthy music, and like you, I agree that some of it should not even qualify as music.
Going back to 1970's one of the first for me, was Fripp and Eno (No Pussyfooting), and it is difficult to all of a sudden say ... some repetition is bad, but in this case, it was just so far out and crazy, that one wondered, what they were really thinking.
As time went by, Eno developed into something else and his stuff is always "pretty" and "attractive" in a very different way ... and one CD simply said that there were several threads and they were mathematically intertwined and started at different times, and I am not sure I could tell one from the other. And he used this live on several art shows as well, probably where he figured it out ... it's out of sync, and it works.
The German version was more melodic, and "knob-wise" as I call it. To me, even though it is rock music, the early Cluster/Kraftwerk(pre-Autobahn)/Neu/Harmonia were a pre-cursor of "New Age" stuff with guitars on it ... didn't bother me, but it did bother folks at the New Age stores here in Portland ... that guitar is noise!
My favorite lies with Klaus Schulze and then Ash Ra Tempel ... whose work is above and beyond the "ideals" of "New Age". Klaus, took the art of the repetition to an art form and then layered it 100 times, and it became nutz and crazy from a figuring it out point of view, but it sure was pretty and exciting. "New Age of Earth" (1974) is, by far one of the early and best "New Age" albums, but will not be listened to by most folks, because it is so different and it also features a meandering guitar, the style that Manuel Gottsching favors.
I tend to blow out neighbors with my high powered AMT Heil speakers ... I move them next to their wall and blow out the loudest crap I can find ... the one you know they hate since they can only listen to this and that. Once, in Santa Barbara, I closed a party, because there were too many people there, and they were not invited. So I changed the music to Amon Duul 2 and drove them out in 20 minutes! I'm waiting to blow out my neighbor Latino ... I have a few Spanish rock bands ready to go, and it will sludge their ears and their rap-mariachi mix so fast, that I think they will shut up for a week or two!