Hello
I'm not an expert, but I somehow managed to roll a set of dice enough times to get 256 bits of entropy. I also added a passphrase.
Dice rolling is an excellent method to mitigate risks of RNGs because you're obviously generating verifiable entropy in front of your own eyes.
Here is a straightforward guide, maybe not for Grandma, but easy enough for non-experts like me:
I assume the process should work on devices that copied the Coldcard's firmware, so Passport wallet may be able to do this process too.