the better way is probably to store this particular sensible password on a piece of paper , stored in a safe place.
That could work for a few passwords, but when you have quite a number of passwords to keep track of, it becomes very inconvenient to store them on paper. It also makes it easy for people with physical access to steal all your passwords.
There are some actions you can took to prevent loss of your paper passwords.
1. Make sure that paper copy is not the only one, make couple of them and store in different places.
2. "Encrypt" your passwords - for example don't write whole password but only some part of it and remember the rest.
Or use simple method to switch some numbers with letters and vice versa. It might suffice to mislead potential thief.
3. Make sure that piece of paper looks inconspicuous - make it look like ordinary note or scribble of some sort.