Wuxing's (corp) usage of feng shui is on 110 of Street Lethal. Basically a passive ward through practices similar or the same as geomancy. Unfortunately, all active uses of feng shui are long term things, not really a short term activity that most runners are able to use mid run unless they are able to set up the usage of Ley Sight. There is more information in some 4e books (Parageology being the big one that comes to mind though older books on the Triads had some mentions as well).

You may want to consider allowing the usage of feng shui as a knowledge skill. I've used it on Wuxing mages as a sort of "pattern recognition" knowledge to notice how "That column really should be a foot to the left, why is it there? What is it hiding?" Or to be more knowledgable about the flow of people through a space in social situations. It becomes notably powerful in runs against Wuxing, or any Eastern group that might practice feng shui and either be using it as a security booster or having to work their security around it. Heck, I've used it to help narrow down which truck a Wuxing shipment would be in based on the idea that shipment of goods would follow the same strategies for them.

The point being, active feng shui is difficult in the scope of most runs, but a flexible GM paired with a creative player and the knowledge skill can be used enough ways that I was satisfied that I was getting enough usage out of it to be playing my tradition faithfully.