How do I write a book and sell it?

Nothing in (B) is under your control except the quality of the book and the quality of the query letters.

The only way to sell great books is to write great books.

How to unfailingly write a great book and sell it in three easy [well, not that easy] steps:

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—Write multiple books, ideally more than one per year, unless the income from writing isn’t especially important to you, and then it doesn’t matter.

A) Learn to write great books.

Original Question: How do I write a GREAT book and sell it?

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—Learn enough about metadata to enter adequate metadata that does not break KDP’s terms of service.

Then cross your fingers in the hope that the agent will be able to place your debut novel with a Big Five publisher and cross your fingers some more in the hope the publisher will actually market your book somewhat adequately and/or a BookTok influencer or somebody like that will pick it up and rave about it.

Also, if you write unreadably terrible books, barely readable books, halfway adequate books, or even good books, they won’t be great books, as specified by your question.

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—You accumulate multiple books that are great, but that your agent can’t place with publishers.

—Put enough time and/or money into promotion that some number of readers become aware that your books exist. This can be a slow build, but if you do no promotion, then readers will not buy your books because they won’t know your books exist, and that’s the way it is.

You can’t build a career by writing ONE great book, unless you’re Susanna Clarke, and given that she’s written just three books in twenty years, she doesn’t have what you’d call a career as a writer. She does have fame, at least in a small way, and if she wrote any more books, they would certainly sell. Who knows, maybe someday she will.

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C) Self-publish, and for this to work, you must do each and every sub-step below, and none of these steps are optional:

—Sit down and write a novel you love that is as great as possible.

—Your publisher drops you because your books don’t sell.

Let’s say you have 3 separate manuscripts and send 1 of them to 12 different agents (4 read same copy). Now let’s say 2 agents each liked separate manuscripts and want to move forward. What would you do as far as transparency and negotiation?

Now that you’ve done step (A), you are ready to go to step (B).

The most common method for achieving step (A) is to follow these sub-steps:

AND

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—Read one thousand novels attentively, paying attention to them so that you develop the artistic judgment to know which ones are better than the others and why.

—Learn enough about description to write adequate, preferably good, descriptions.

—Repeat, writing another two to ten novels, until you have learned how to write great books.

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The only way to write great books is to learn to write great books. There are zero shortcuts by which to skip this step.

—Learn enough about formatting to make the interior of your book look like a normal book.

—You get fed up with the crappy job your publisher is doing with your books.

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There is no way around step (A), sorry. If you are hoping for a shortcut, nope, there aren’t any. Therefore, if you want to write great books, you are going to have to learn to write great books.

—Learn enough about covers to get or make adequate covers.

Also, if you go for (B), you should be aware that you are probably going to want to transition to self-publishing eventually for one or more than one of the following reasons:

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If (B) doesn’t appeal to you, go to (C).

B) Learn how to write good query letters and query fifty legitimate, non-scammer agents, ten at a time, until an agent offers representation.

—You decide you’ve built a sufficient readership to strike out on your own.

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However, if you want a career as a novelist, you’re going to have to write a whole lot more than three books per 20 years. In traditional publishing, one book per year, or even one book per two years, can be adequate.

However, traditional publishers can certainly give you a boost, plus editors at traditional publishers are generally, in my experience, pretty good at editing.

—Also pay attention to which ones you actually love the most.

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If you write unreadably terrible books, then no one will buy your books because people only buy books they actually want to read, and that’s the way THAT is, period, so there’s no point looking for a way to fool people into buying your book when no one sane would ever buy it.