garden as architecture
I think it was Aaron Betsky who described architecture as a sequential and spatial experience.
That is how I see garden making. It is very important to grow high things so you can't see the whole garden at once. Winding paths enable changing garden views, as opposed to just looking out of the window.
I, like many gardeners, used to talk about taller plants suitable for the back of the bed and lower growing ones for the front. But of course, where the back is depends on your viewpoint.