I finally landed a 6-figure book deal after 20 years of trying to become an author. Here's how I did it.

• Melissa Petro is a freelance writer, writing instructor, and author in New York City.
• She tried to sell her memoir for years before selling it at auction in November for six figures.
• To fine-tune it, she became an avid reader, wrote as much as she could, and found the right agent.

Scoring a book deal is always an accomplishment, but after I dreamed of becoming an author for more than 20 years, selling a nonfiction project for six figures to a Big Five publisher felt both astonishing and hard-earned.

Like a lot of people, I'd always secretly harbored ambitions of becoming a writer, but I didn't start taking my craft seriously until my mid-20s when I invested in a Master of Fine Arts. Even then, writing remained a hobby for another few years.

In 2010, I lost my job in elementary education when an essay I wrote was publicized by the New York Post and the whole world — including my then-employer, the NYC Department of Education — was made aware that I had worked as a stripper and prostitute before becoming a schoolteacher.

I turned a humiliating experience into a flourishing freelance career, and I got serious about my ambitions to become an author.

In November, I sold my book, "Shame on You: How to be a Woman in the Age of Mortification," to an editor at Putnam Books, a division of Penguin Random House. Here's how I did it.

First, I accepted there are no shortcuts

Some people think that having a scandalous story means a book deal is in the bag, but that's not always the case.

Days after my story was publicized, my writer friends and other industry folks begrudgingly congratulated me on my presumably imminent book deal. People who'd never even read my writing assumed I'd have advantages because of its steamy subject matter.

But having an interesting story isn't enough. If you're writing a memoir, you need to have a handle on what actually happened, a clear understanding of what it all meant, and an answer to the question: So what? At the time, I could recall the events of my life with vivid clarity, but it would take years of inner work to turn that lived experience into wisdom.

Beyond knowing what your personal experiences meant to you, and how they changed you as a person, a story needs to feel relevant to its readers — otherwise, it belongs in a diary, not a bookstore.

To learn what readers care about, I became an avid one

Before I called myself a writer, I was a reader. Other people's writing shows us how it's done. I read a lot of memoirs, self-help books, and cultural criticism, as my book is a blend of these three genres.

I also joined writing workshops, where you'll not only learn about craft but also read mentor texts and other aspiring writers' work. When I couldn't afford classes, I traded pages with my peers.

As a writing instructor now, I've critiqued thousands of manuscripts. Not that my students' writing is all bad, but even reading bad writing will make you better at the craft.

I wrote — a lot 

Besides therapy, writing and publishing mostly personal essays is how I made sense of my situation. I've worked as a full-time freelance writer for the past decade, which has helped me clarify my thinking on issues important to me. I've gained skills, and I've built experience working with editors.

I also developed an audience. Amassing hundreds of bylines made me desirable to agents and, eventually, the editor who bought my book.

It took about two years to write the book proposal, and I wrote the book in about nine months.

I found a top-notch agent

Even after my unpublished manuscript was a finalist for a PEN award, I struggled to find a literary agent interested in selling my book. My first agent was lukewarm on the project, but she put it in front of editors anyway. In retrospect, it's no surprise that book didn't sell.

After that, I cycled through a handful of even-worse agents: the agent who suggested I shelve my memoir and write about something else entirely; the agent who was too busy, he said, to meet in person "a second time" (we had never met in person); and the agent who offered me a glass of Champagne (I'm sober — and if she'd read my manuscript, she'd have known that).

The right agent is the one who's in love with you and your writing. They'll make sure your idea is good and that the writing they present to editors is your very best. It took five years to sign with my current agent. She was a Facebook friend of mine whom I saw left her job as a book editor to become a literary agent, so I reached out to her.

After working with her to craft my book proposal that ultimately sold, it was a different book — a better one.

I stopped comparing myself 

My book was sold at auction, and there were two rounds of bids. All the bidders went up the second round, but the winning editor was the highest bid. I also liked the direction she wanted to take the book, so she was the clear winner.

I have friends who scored book deals straight out of grad school based on a single viral essay. Good for them — I mean that sincerely — but that's not how it usually works. Folks think "sex sells" and that exposure equals opportunity. For women, in particular, our talent and tenacity are frequently dismissed. But nothing about the journey has been easy.

That makes success even sweeter.