Here is another extremely common theme. This came from a sicilian where my opponent, an FM, played very unambitiously and seemed happy to try to just draw. He just played g3 overdefending his f4 pawn. Black needs to figure out a way to make things start happening and as always, a simple tactic does the trick.
This is another problem where the solution does not involve mating the king, or immediate material gain. More positional tactics! Try to also find white's best defense to black's idea.