Foreshadowing serves the purpose of letting the reader know something big is coming. It is widely used in the mystery genre, but is not restricted to mysteries. Foreshadowing creates suspense, especially where you think the chapter might need some boosting, something to get the reader turning the pages. It is a little recurrent detail that warns the reader that something is brewing, that something does not make sense, that something is out of place and the reader is waiting for this to be explained. A fiction novel without foreshadowing means the reader does not have expectations beyond what they are reading. Anticipation sometimes is more exciting than the actual event. It gets the reader to anticipate and panting for what is coming.
What kind of foreshadowing is there? Foweshadowing has two purposes: prepare the reader for an event that would otherwise sound unrealistic, and to create suspense and tension.
Foreshadowing helps clarity. If an event falls down on everyone in the novel unexpectedly, it creates a surprise. Often a surprise is perceived as coming up too fast, startling the reader and confusing him or coming out of nowhere, like an afterthought.
Romeo and Juliet keep mentioning they would die if they were apart. This foreshadowing creates tension and drama. When it actually happens, it is believable.
Symbolism can also play a role in foreshadowing, preparing for the denouement, creating an atmosphere, suspense and tension. Symbols of life, that will prepare for a positive outcome, can be flowers blooming, seeds, fresh water, summer, spring, clear skies. Symbols of death that prepare for a fatal outcome can be winter, storms, withering plants, dust, silence, night, gloomy nature around the character.
Use visions, omens, and dreams if you write fantasy. However, do not abuse them and make them subtle. Sometimes visions and dreams are too obvious and bother the reader. Readers prefer a mysterious vision or a clouded clue. If the hints are unclear, they make the reader think and prepare for something to come but he is not sure what. That creates tension.
Examples:
In Harry Potter and the Philosopher's Stone, Firenze says "Mars is bright tonight" because the Centaurs predicted that Harry would die in the forest.
In Harry Potter and the Half-Blood Prince, Trelawney says, " the first rise from a table of 13 will be the first to depart..." The fact is in Harry Potter and the Deathly Hallows, the 13 survivors of the Aerial Battle have a drink together and Lupin is the first to rise and die.
J.k Rowling declares, “It’s rather funny really that next to no one realized that the snake Harry set free in The Philosophers Stone, turned out to be Voldemort’s final horcrux nagini.”
In one of the first chapters, Hagrid delivers baby Harry on Sirius Black’s motorcycle. Sirius is not mentioned for two more books.
In Summer Tree, the author Guy Kay uses foreshadowing like a storyteller, pulling in the reader every time he sees the attention relaxing. He uses prophecy. The author also hints at the path the characters will take based on their personalities. Other characters hint that Paul suffers from something. Then, the theme of suicide is brought up; finally he cannot handle intimacy or Kevin playing Rachel's Song. It is obvious, after all the foreshadowing that the path of this character will be dark and tormented. He can only choose the path that will end his guilt and pain.
Some tips for writing foreshadowing:
1) Do not give away what the event is going to be. Just hint at what is coming, intrigue, reel in.
2) Plant information throughout the novel that add up to a believable result. This is especially true in fantasy novels where so many elements can appear to come out of nowhere. The world you build must be believable for the reader to keep reading, otherwise your reader will say “Come on! Who are you kidding?”
3) What you foreshadow has to have a crucial impact on the end of the story, maybe turning the plot around. In screenwriting, foreshadowing is called “planting and payoff” because there needs to be a payoff. It is not a technique you can use cheaply. It builds to the “aha” moment.
4) Do not mention an object or a person over and over and then suddenly forget about it. That’s where it is important to re-read your novel only for details, make a list and tie the loose ends.
5) Mention an event that will happen in the near future, maybe through a newspaper clip or through people gossiping.
6) Mention an important theme that will come up later.
7) Mention a person the protagonists will meet later in the story or a skill they learned that will reveal to be important.
8) Mention objects that the characters react to, a color they cannot stand or a perfume they find overwhelming.
9) Foreshadowing is not gratuitous. Make sure your element or event foreshadowed stem from the plot.
10) Do not create fake suspense. It is disappointing and makes you pass for a cheap writer. If the hero hears an animal growling, do not make the growl materialize into an inoffensive dog.
11) Make the characters worry about what could happen or about another character.
Foweshadowing can also help the story in a way it misleads the reader to thinking something is happening when something else is actually going on. However, to make this work, you need to have consequences. You cannot make the reader believe one thing then hit and run. You need to use what you foreshadowed to advance the plot. One of the protagonists needs to believe in what is foreshadowed along with the reader. That way, there are consequences. In mystery novels, these are called "red herrings" or false clues. They are placed in the novel to increase the confusion of the reader and produce a thicker mystery. Red herrings divert the reader from the main plot. They force the reader to make wrong conclusions so that when the reader discovers what is really going on, he has one of those “aha” moments mysteries are made for.
Example: The character of “Bishop Aringarosa” in Da Vinci Code by Dan Brown is the red herring. The reader suspects him to be the mastermind behind the conspiracy in the church. He is suspected throughout the novel. At the end of the novel, the reader realizes that he is innocent and he was placed in the novel only to make the reader’s goose bumps rise.
In Agatha Christy novels, the reader always suspects the wrong person and the person who seems to be innocent is actually the person who committed the murder.
Foreshadowing and red herrings have the same purpose: to keep the reader guessing. They are placed in novels to surprise the reader and prevent the reader from guessing the ending, which adds a lot of value to the fiction. They are vague, seem without purpose and arbitrary, but they always have consequences and deliver their promises. If you show a weapon from the beginning of your novel, the weapon has to strike someone, anyone, even someone the reader would never think could be harmed by it. They are added once the plot is written. They should be sparse but appear at the most crucial moment, when they can make the most impact. I can be a sign on a road, a perfume or a building, a person or a skill. The sky’s the limit.
Reference:
Nine Examples of Foreshadowing in Fiction by Harvey Chapman
http://www.novel-writing-help.com/examples-of-foreshadowing.html