Good Cop/Bad Cop always gets results, and is applicable in a wide variety of situations! Try it and see your life improve:
You: Hey, boss, I was really wondering if I could have a raise.
Boss: Sorry, Henderson, it's these cutbacks. They're affecting all of us.
You: Hey, that's fine, chum. You want a stick of gum?
You: SHUT UP, YOU DON'T GET ANY GUM!
You: DON'T MAKE ME HAVE TO TELL YOUR FAMILY THAT YOU TRIPPED AND FELL INTO THIS CROWBAR AND THEN ROLLED YOURSELF IN A CARPET AND THREW YOURSELF OFF THE SAN FRANSISCO BRIDGE, SCUMBAG!
Boss: I like the cut of your jib, Henderson.
Stranger: Uh, you see The Help? I just saw The Help.
You: Sure I did, pal, sure I did.
You: I'M LYING, DIRTBAG, I'VE NEVER SEEN THE HELP! WHAT ARE YOU, AN IDIOT?
You: I forgive you. Let's hug it out, compadre.
You: I'M LYING AGAIN, I DID SEE THE HELP! I ADORE EMMA STONE, I THINK SHE'S A GREATLY UNDERUTILIZED ACTRESS!
You: SHE WAS WONDERFUL IN EASY A, THAT WAS A STARMAKING ROLE!
You: SHE'S GOT A LOT OF POTENTIAL.
Roommate: Hey, you left your towel on the floor again.
You: Hey, buddy, don't worry about it.
You: TELL ME WHAT I WANT TO KNOW! (backhanded slap)