These are fairly generalized overviews of the rock gardening and zen approaches:
Japanese Tea Garden
They are not designed for the advanced purist who is already well ahead of the basics, that is not the intent.
The inent is to familarize the hobbyists who is interested in the next step in design and concepts. Most folks have gotten a decent grip on growing plants, now they are faced with scaping.
I think most folks see this steop and really freak out. They have no idea what to do and feel woefully "artless".
But it's not that bad.
A little reading and educating one's self is not going to be nearly as painful or costly as learning the science.
Copying ADA tanks is one thing, but moving beyond that means you may want to consider the origins and move beyond what Amano says and try your own sense of art and aquascaping from a basic understanding.
Japanese Stroll Garden
Both of these links have a good back ground on some basic ideas and their history.
regards,
Tom Barr