Plot Hooks/Twists

One thing that always seems to add a bit to a campaign (at least to me) is the good ol' plot twist. For some reason, I like doing them, unfortunately, they're usually cliche and because of this, they really aren't entertaining. Suddenly saying "you're working for the bad guys" doesn't ring as close as it should I feel. As such, I am trying to think how to twist the story in an interesting way that doesn't become generic and boring for everyone involved. Ultimately though, I want to think of something. Betrayal always adds a bit of intrigue I feel. The double agent or some higher up screwing around and messing things up always adds that bit of fun (think The Third Man with the American screwing around). Lots of fun.

Suggestions on how to make this work? Any tips? ideas at all? Comment!