I read a lot of posts on this topic. People offer any, even fantastic options. Each of them has advantages and disadvantages.
I found a simple and understandable solution. We have Private Key, for example

ch74nhcwrf4439nfv340fvq3rvn23mf2fj20f204f

 You can leave it on the computer + print and put somewhere at home + make another copy on the email.
It is necessary to do only one thing. Change 4-6 characters.

 For example, change ch74nh to krw49d    Further, it is enough to remember these 4-6 characters.

Now if a hacker gets access to your computer and finds a Private Key, he can not steal money.

 But we can do even better. Replace characters not at the beginning of the Private Key, but somewhere in the middle. For example, the date of birth your wife on 12 December. You definitely will not forget this date. We change the symbols from 12 to 17.