Flaubert said of Madame Bovary that she was himself. We can’t help putting something of ourselves into just about every character we create. What if the basis of your fictional character is someone you know but you don’t want them to know it?

A warning. Imagine that your book has been published and your friends are around you at your launch.

The minute they open that book of yours, many of them will scour it looking for themselves. And they’ll find themselves in the most unlikely places.

This seems to be first cousin of their belief that everything in your book literally happened to you, no matter how far your book’s world is from your life. All we writers can do is shrug and say we made it up:

‘So you killed your husband and buried him in a volcano in Borneo?’

‘It’s fiction but if you want to think that, feel free.’

‘But that sober, handsome warrior chief who’s seven feet tall and wins prizes for his shortbread, he’s the image of your husband, isn’t he?’

‘If you want to think that, feel free.’

As long as they buy your book, they can think what they like.

You do want to avoid libel though, as it’s expensive and exhausting and publishers do not enjoy it. So how do you fictionalise a real, living character?

It’s simple really: just change a few vital things.

On one side of your page or screen, jot down a few details about the real person you want not to write about: full name and nickname, physical description, age, ethnicity/provenance, education, finances/job, family status, address, living alone or who with, essential elements of personality, sexual orientation, secrets and world view. A few sentences of pub conversation are enough for that last one.

Down the other side of your page, name your fictional character and take a few minutes to imagine who they might be. Then, opposite the list you’ve made for the real person, describe your fictional character aspect for aspect.

Make sure that some important aspects are radically different from the real person. Two or three will be enough.

Now you are ready to do your character interviews afresh to build and discover this new person. Drill down deep, unlock those secrets and that voice, and soon you should find yourself in the company of someone unrecognisably different.

That’s all there is to it! It’s especially important to give your fictional person a different name from the real one – please don’t be tempted to give them the same initials or even the same rhythm in the name – and this exercise works especially well if you alter age, gender, sex, education, ethnicity and/or sexual orientation.

It’s worth giving a thought to why you are incorporating a real person into your novel when there are so many wonderful characters to be made up. Have a private scribble about why you feel you must write about this person. Why do they fascinate you so much? Do they encapsulate something about your story’s theme that makes their presence invaluable? Or – it’s important to be honest with yourself now – are you writing this real person into your work because you want to have the last word in some way, even revenge?

If the last is the case, your book may well suffer. My character interview shows you how to combine closeness to your characters with (towards the end) the vital detachment that keeps your story in balance and stops it straying into cliche.

Next week we’ll look at how we write about characters who are long-term friends.

Have a happy writing week!