Yeah, the "3-2-1 rule" is probably the easiest to explain to an inexperienced user.

I think the seed plate stuff is overemphasized in the Bitcoin community. 3x paper backups (home, bank box, and family/friends's house) is enough for anything other than an extreme edge case. Your house isn't going to burn down, at the same time your parents' house gets hit by a tornado, at the same time your bank floods.

And I thought about recommending an air gap computer solution, since it's so useful for verifying keys, generating seeds, and additional encryption. But I think it's too much for a noob guide like OP is making. Too many places to mess up and the message should be simply "never put these seed words into an phone/computer!"