Japanese garden design is about as hard to understand to Westerners as the Japanese language is. The relationship to the rich and ancient eastern culture adds to this difficulty. The practice is not just a style of landscaping. Rather, it a statement that delivers a specific meaning. Adding further to its complexity is the influence of fengshui and its borrowings from Buddhism and Chinese culture.
The intention of Japanese garden design is to use nature to make a statement. The main element is symbology, most of which is influenced by Shintoism and Buddhism, which is where the gods inhabit nature. This adds even more its cultural complexity making hard for us to understand.
Since the garden is making a statement or telling a story, the first step is to determine what story you want to tell. What is it you want to communicate to the world with your garden? It might be a good idea to decide in broad terms what you want to say, and then through some research find out how Japanese would go about communicating that truth, concept or story with a garden.
Another outstanding feature of Japanese garden design is that the main point is not to be beautiful or showy. The appearance of the garden is not its purpose, but rather the message is the purpose. Beauty is the after thought, so to speak.