The guide to writing reader-insert fanfiction

Preface

The first thing a prospective reader-insert writer must consider is this:

Do you want to write a reader-insert or a fan character?

If you want to write a fan character x canon character fic, go forth and do that! It's fun! I've written my fair share of those. If you're lucky, you might even get other people into your ship. (Yes, I'm Just That Good.)

No, you say, you want to write a reader-insert fic.

But I'm a reader-insert fic connoisseur, and I won't take your word for it. I want you to contemplate what you want to do, so I'll ask you a couple of questions.

1) Do you want to describe the main character in detail?
2) Does your MC have a thorough backstory?
3) Does the MC have original characters as close friends or family?

If you answered "yes" to any of those, I would recommend you make the MC a fan character and go wild!

No, you say, you have your mind set on writing a reader-insert fic.

Alright, I say, then I'll give you some tips.

The actual meat of the matter

The most important thing about writing a reader-insert fic, which I feel many authors forget, is that the reader-insert needs to be relatable. Not just to you, not only to your peers, but as many Readers as possible. A universal reader-insert, if you will.

Tip #1: Describe the reader-insert as little as you possibly can.

I imagine some of you are confused. You thought description was good? Yeah, it can be. But it has its time and its place, and even then, I recommend following the rule of "approximately threes": only describe approximately three things in one go, unless you absolutely must describe more—five is usually the hard limit.

But with reader-inserts, less is more. Your Readers will be of various heights, weights, ethnicities, even ages, they will have different hairstyles, with different hair textures and colours. If your reader-insert is universal enough, they may be of different genders. The moment you say that the reader-insert looks up at someone who's 155 cm tall / 5'1", you've made the reader-insert less relatable to many a Reader.

Do you want to have the love interest carry the reader-insert bridal style?

Ask yourself: Will some Readers need to suspend disbelief to believe they could be carried by the LI? What if the reader weighs a lot? Is the LI very strong? Or do they perhaps have superhuman strength?

Do you want the reader-insert to be shorter than the LI?

Ask yourself: How likely is it that you have Readers who are taller than the LI? If the LI is the aforementioned 155 cm / 5'1" short stack, you should probably avoid that. Even Japanese women's average height is an inch more than that. On the other hand, if your LI is over 2 metres / 7 ft tall, that's probably not going to be a problem and you can go wild describing a bit of a height difference. Anything shorter than that, and I'd recommend erring on the side of not specifying height differences.

Do you want to describe your reader-insert's body shape or level of attractiveness?

Keep in mind that not everyone has the same relationship with their body. Some Readers will scoff if the LI describes the reader-insert as beautiful/hot/cute. Similarly, describing the reader-insert, for example, as having a round chest, will exclude the small-chested Readers.