I photocopy on both side all of my bank cards and credit cards, photocopy of my passport.

I also scan them to store on a memory stick and a remote server.
I also have some cash stowed with the backup documents (emergency cash).
I also keep a copy of canada direct and all of the T&Cs and reservations, especially the plane ticket rules.

Having no status, I don't bother having a copy of the T&Cs of my FF programs