My friends make fun of me because I keep credit card and ATM receipts in my wallet. If you are familiar with the Seinfeld episode where George had a very fat wallet/billfold because of his receipts --- my wallet can sometimes get to that state. I don't keep the receipts as keepsakes. I keep them because I'm paranoid about leaving my banking information in the trash. So - what I do is I keep them in my wallet - then once a month - I shred them using my shredder at home.
Last Christmas - I discovered that Muji actually has a portable shredder. It doesn't need electricity to operate - you just turn a know clockwise - similar to the motion you make when using a pencil sharpener. It's very handy - and can even fit in your purse or man-purse.
I excitedly showed it to my friends --- and they were not amused. They asked me why I can't just tear up the receipts using my bare hands. Uh-duh-uhm. I don't have any answer to that question.