c. Diversify Brands of Hardware Wallets: Some coins can be stored in Trezor while the remainder can be stored in Bitbox as the case maybe. This way, bug or an exploit in one type will not compromise everything.
The more you split your holding in different wallets, the more failure points you have created.
c. Also ensure to keep you location and travel plans undisclosed in order to reduce profiling by potential attackers.
I use this one very well. Even my closest person might not know my travel plans till a few minutes to the movement.