I'm glad you found it interesting, though real wisdom manifests as at least double-checking any chemistry you'll find on the net, common sense, and staying on the side of caution. In the case of soap-making, it basically boils down to watching out for splashes, having some eye protection and keeping it away from aluminium (reacts to produce hydrogen gas). Lye will also affect wood, so it's best to do the entire process in/with glass, ceramic or resistant plastic implements and containers, aim for sturdy. Also, here's one lesson I learned three minutes too late a few years ago: dissolving lye can make your solution hot enough to significantly deform PET bottles, up to the point of making small cracks, even though it doesn't react chemically with it. That said, if you have questions or would like to know more, feel free to ask here or via private message. It's a fun project with plenty of room for experimentation, so I hope I didn't discourage anyone.