Password Managers are the new goto for obtaining all passwords and web browser zero days make it very easy to lift and then use for a variety of purposes. A simple lined small note book is good, but made secure is best, yet how would you make a pwd note book secure from someone else? This even applies to devices like bank cards and other things which needs a security code of sorts.
Keep your password manager offline with Keepass2 USB keyboard plugin for Keepass2Android [1], but I'm not sure how well it works. Too-fast USB keyboard input does seem to have issues (the open issue seems similar to things I've seen an AlphaSmart 2000/3000 do in USB emulation mode; PS/2 always worked fine).
There's also this other project, which seems more generic/difficult [2]