I'm definitely a mood reader, as in my mood determines my choice, but once I start reading that book, it sort of locks me in to that setting/time/atmosphere and I think that makes it hard for me to switch back and forth. If I read multiple books with similar settings I start mixing up the characters. :P
I used to use boarding passes all the time when I traveled for work - they make the best bookmarks! I also used my train tickets while I was in UK/EU. They pop up in my books once in awhile and make me smile. :)
Multiple books with similar settings are a nightmare. I do tend red books in parallel that are different to each other to avoid exactly that problem of mixing up characters.
I used to use boarding passes all the time when I traveled for work - they make the best bookmarks! I also used my train tickets while I was in UK/EU. They pop up in my books once in awhile and make me smile. :)