An aspect that you need to keep in mind when writing is what you want your readers to feel as they read each section. Fiction writing is, essentially, trying to re-create the emotion you feel for the scene within the body of the reader, and in that, you need to always be aware of how you’re communicating the details. Importantly, what you need to be careful of is what words you use. Sometimes an out of place word can ruin a perfectly good set up – you wouldn’t have the word ‘chook’ in the middle of a scene of romantic resonance, for example. Careful word placement, and even word themes, can help build scene depth, and characters individually.
Here’s something that’s worth trying – assign each character in your story with a colour, based on their personality and traits, what you know of them. Once you have the colours down, write down words you associate with those colours – make a word cloud of 10-20 words that you’d link to it. For example, red might be associated with fire, stop, heat, fast. Once you have your words down, as you write, try to use those words in your descriptions of those specific characters and their actions. What this does is it builds a theme around that specific person – you associate those words with that colour for a reason, and readers will to. With red, anytime those references come up, people will have an association with them, and thus, the character, which creates more of a theme or personality type for each. This can help develop a distinctive persona, making them identifiable in more than just physical attribution. Those words form part of who the person is, and this can help develop depth and definition in a character’s being.
This won’t work for all writers, some may even find it restrictive to their process, but it’s worth trying, even with just a short piece, just to help build more presence around each participant in the story. Even try it in real life – think of someone you know and what colour you would attribute to them. What words do you link to that colour? Do they relate to the person? Normally, you’ll find they do, and this adds to the emotional linkage between character and reader.
It’s worth trying out, just to see what comes of it – even if it’s not for you, it might help open your mind to another way of thinking and improving character depth.