***The following contains spoilers for the Australian television movie Little Oberon.***
Here is an example from a movie (Little Oberon) of showing the audience key elements of the story instead of telling them. ("Show, don't tell. Show, don't tell": something my writing teachers always drummed into my head.) It's much easier to show in a visual medium such as film, but you can still use these concepts in a book.
In the movie, a teenager was trying to find out who her real father was. She doesn't find out herself during the course of the movie, but the audience does if they are paying attention, because the audience is let into the secret by a few brief scenes that need to be interpreted.
In one scene quite early in the movie, the teenager orders a cup of tea at a café. She quickly spoons three heaped sugars into the cup and stirs it quite lightly, tapping the spoon on the rim of the cup. She's not really paying attention to what she's doing, but the scene stands out because she's being watched by a boy who's interested in her.
Later, near the end of the movie, a man is offered a mug of tea together with a bowl of sugar. He heaps three sugars into the mug, stirs lightly, and taps the mug with the spoon. It is so similar to the manner in which the teenager took her tea that the audience is bound to be left with an "Aha" moment. This man is her real father.
It is now that the audience realise that there were other clues - also shown - to confirm this theory. We hear this man speak with an Irish accent. When another character tells the teenager a well-known Irish saying, she is entranced. It is clearly the first time she has heard the saying, but she takes it to heart, and repeats it at the end of the film - after the duplicate tea-stirring scene.
But none of the characters in the film notice this similarity - at least not yet. The film ends leaving open the possibility that the characters might still run into each other and notice these similarities. Of course, there's also the possibility that some audience members would not have picked this clue up - but that doesn't matter since it's only part of the story. It's more important that the audience who did notice it have enjoyed the little secret twist that only they are allowed to discover by themselves. There is no audience hand-holding by having the character turn round and tell the audience what just happened: "Wait a minute. You take three sugars in your tea, just like me. Are you my father?"
It's important to trust your readers to discover and interpret the clues you leave when you show part of your story. When you decide over and over that you must confirm the clues by telling the reader what is going on, you really show the reader that you don't trust her to be intelligent enough to pick up what you mean. And you also show the reader that you don't have enough faith in your own ability as a writer. Let go of some of the control of your story.