Whoa, easy does it Bill.
I think Feng Shui is rooted in solid design principles, and if you follow the most basic of those principles, you'll end up with a nice scape. Don't get me wrong - moving a tree to increase prosperity or painting a certain color to improve health is out there, and not something I subscribe to. But just having a handle on what they call the "5 Elements" (Water, Wood, Fire, Earth and Metal) will get you a long way toward creating a Feng Shui inspired garden.
And the properties of each of those elements is really pretty intuitive; having the water element in a design means using blues and blacks and curves and is supposed to inspire a contemplative mood, fire uses reds and oranges and acute angles and corners (ala flame) and is supposed to inspire action, lively conversation and maybe public status (like the red power tie of years gone by).
In the end I think any good salesman needs to have at least a mild acquaintance with whatever the latest thing is, just to do a good job selling. Speaking the "language" will go a long way toward inking the deal.
On a side note, if you want a good book for quickie reference, check out Feng Shui in 10 Simple Lessons (see
suggested reading to check it out at Amazon.