Rules are made to be broken... Well so are stereotypes. Write down three stereotypes from three completely different genres (ex: romance, mystery, fantasy, ect...). Now base your story off those three stereotypes, but break those stereotypes along the way.

Examples: The nerdy girl doesn't end up with the bad boy, even though it seems like they might.

The killer was helping the detective all along and were actually their best friend. But instead of getting away or killing the detective they turn over a new leaf.

The prince turns out to actually be the villain.

Bad examples, I know.