Sometimes when my coworker is having a bad day...

She really looks out for us and our whole department. She isn't a higher position than the rest of us, she just far surpasses us in experience and has a very sharp eye for detail. Our boss does not really look for these things and very often will argue to do things the wrong way (we'd just listen to the boss if we didn't have regulatory agencies watching us...) Sometimes when my coworker is having a bad day (after arguing with our boss that something is being done wrong) I will go to the vending machines at work and get 2 kitkats. I give her the 2nd one and say that the machine gave me two! And that she can have the second one. I can't give her a raise but I will always give her my "second" kitkat.