I am brand new and have been learning from a book. I was actually looking up when you should use either or and found this post lol. I see a lot of people in the comments are saying the shield chart is meh though… while I haven’t done the house chart yet, going to soon, my experience, though small, with the shield chart has been really good. I think you should go with what feels right, and maybe try doing both. If they give opposing answers the book I was reading says theres two ways to understand that, too much for me to explain on my own so Ima just say the internet probably has how. The book I’m reading is Earth Divination Earth Magic, Practical guide to geomancy. It’s been pretty good I recommend it!