Of course I have them backed up as well. I could never memorize 24 words seed phrase no matter how much I put effort into it, not worth the hassle as well.
All the typical ways. But my PRIMARY way is my memory.
Anyway, this is how I did it. (I'll use a 12 word seed as an example, but I actually did it with a 24 word seed phrase as well. It's a bit harder, but I used the same system I outline below, modified for 24 instead of 12 words).
I don’t understand the need to always stick with
24 word seed when 12 words can securely protect
BTC-stash. Bruteforcing
12 word seed involves searching through 2
128 possible combinations. This number is far beyond the reach of modern supercomputers within any feasible timeframe. Personally I use 12 words SEED extended with the passphrase which adds the extra level of security to my stash.