A nice Aquascaping is like a nice photography (don't forget Amano is a photographer!)
I will add:
- be carefull not to put the real focal point in the center of the aquarium (except if very symmetric!)
- follow the golden rule or the rule of third for the real focal point
- think shadow/contrast by the leveling and adequate lightning position and even cave who create shadow
- white area (sand per example) can attract the eyes from the primary focus point
- in north America, we read from left to right....focal point on the left will look more natural...but it depend!
- triangle are very dynamic for the eyes....valley...wood and rock angle....
- the aquarium side are like picture frame, kept some space
- overall sense of balance is important
- "complementary" color and tent are important between plant, sand, rock, wood, etc.
- like it was said before "less is more" or the "minimalist" approach can be the right way to go...
I believe lot more rules can apply to aquascaping.
Photographer will better understand what I am saying