Your plot is the chain of events in your story. A theme is an idea that underpins everything. For instance, the plot of Kafka’s Metamorphosis follows a man who awakes to find himself transformed into a monstrous vermin. However one of the novella’s main themes is the effect of money on a family. Many stories have multiple themes that intertwine and play off each other.
You don’t need to be heavy handed – your readers don’t want to be hit round the head with obvious themes. It’s an example of show not tell – show how the themes reflect in your plot and characters.
Artists create harmony and mood in a painting by choosing a palette of colours. You can do the same in your writing to reflect your themes.
Here are a few ideas of how you can bring out your themes.
See things through the eyes of your characters
A theme preoccupies your characters. If you’re writing about love, your characters will be worried about their love lives. If it’s about triumph against adversity, they’ll triumph against adversity… You get the idea. When you look through the eyes of your point-of-view character, you see a world where anything reminiscent of your themes are heightened. So if your characters are lovelorn, describe a world of empty streets, joyless junk food and cold beds. There will be other things in your world that you could choose to describe, but your character (and by extension your reader) are too preoccupied to notice those things. This works the same in third person as it does in first person.
Choose your words carefully
An extreme of this technique is the Leitwortstil – the deliberate repeating of words or phrases that anchor your story. But a more subtle way is to use words that reflect your themes. This is the same as a painter adding a yellow to their colours to warm them up – if parts of your story are about hate, use sharp words and withering adjectives.
Motifs are recurring elements that have a symbolic relevance in your narrative. In a story where your character is re-evaluating their lives at a late point in life, a sports motif could be used to suggest an underdog triumphing in the last minute. Metamorphosis uses food as a motif that symbolises its theme of being the breadwinner in a family and how that affects relationships.
Theme your character profiles
It’s fine working out what your characters’ mothers did for a living and what they have for breakfast, but are you actually going to use that info? When you write your profiles, try jotting down your main themes and writing down how they affect each of your characters. Let’s say your themes are freedom, sacrifice and the value of art. For each character, write down the level of freedom in their life, the sacrifices they’ve made (or will make) and how art affects them. Soon you’ll have characters who reflect your themes and have a real resonance with the overall narrative – even if they’re there to provide contrast and insight into your protagonist.