I habitually use "Thank You" for even the littlest things. I say "Please" for even the slightest request. I NEVER group them together as "Please and Thank You" (would get killed for taking the short way out). I NEVER hold anyone responsible for actually completing a request made by me. I NEVER expect ANY kind of reward for doing the necessary duties.
This was how I was brought up. Don't give me this "kids aren't grateful" and "Kids need to learn their manners" shit. It's only on forums and IRC that I EVER act like a bitch.