I get it. Finishing a book is hard.


Turning a messy first draft into the bestseller you've envisioned? That's even more daunting of a task.


Whether you're struggling to find a literary agent, or you're looking for someone to guide you in taking your book from good to great before you self-publish it, I'm here to help.

San Diego Author and Book Editor Stephanie Diaz

I've been an aspiring writer for over ten years, and a published author for six. I know how terrifying it can be to slog through query and submission hell. I'm here to hold your hand through the process, help you strengthen your voice and your craft, and be both your mentor and champion as you turn your dreams into reality.

What Do I Offer?

I offer manuscript critiques, book coaching, and nitty gritty editing, from line edits to final proofreading to make sure all your i's are dotted and your t's are crossed. I'll help you see where your novel is the bee's knees and where it still needs work. I specialize in sci-fi and fantasy manuscripts for all ages, but I have experience editing most genres of middle grade and young adult novels. I selectively take on adult thrillers, historical fiction, and romance, and non-fiction projects (memoirs, self-help books), as well.

Why Hire Me?

I landed an agent and a 3-book deal with Macmillan Publisher's (St. Martin's Griffin) at age nineteen, before I graduated college. It took years of perseverance to get that book deal, and I wrote many bad query letters before I learned how to write a good one, but I had an almost 50% request rate when querying the Extraction series.

“It was absolutely amazing working with Stephanie. She was a huge part of my success with my query letter and I'm so happy I worked with her!!!!”

Namina Forma, author of the New York Times-bestseller The Gilded Ones

After I landed my book deal, I spent a year interning for The Bent Agency to

learn how to read and assess manuscript submissions for potential publication, so I know first-hand what agents are looking for in debut novels. I've served as a mentor in online agent-pitching contests, taught writing workshops through SCBWI, and for the past five years, I've been working as a freelance editor with numerous satisfied clients in helping prepare their query letters, synopses, and manuscripts for self-publishing or submission to agents and publishing houses.

I know how to craft a tightly-paced plot, I know grammar (I'm well versed in the Chicago Manual of Style), and I can help you strengthen your skills, too. I know how to write a high-concept pitch that will sell. I will help you take your novel to the next level without sacrificing your unique voice and vision. When it comes to edit letters, I've been on the receiving end many, many times, so I can promise I'll hand over a kind and respectful, but always honest, critique of your work.

Services & Pricing

Here is a sample of some of the services I offer, along with my rates:


Query Critiques - $60

​Preparing to submit your manuscript to agents? The first thing you'll need is a polished query letter with an eye-catching pitch. I spent nine years querying three manuscripts before I found publication, to the point where I learned all the tricks--and pitfalls--of query-writing, so I can help you out! This service includes up to three rounds of revision.


Synopsis Critiques - $90

A synopsis is another piece of material you'll need when submitting to agents and publishers. Trust me, I know how tough it can be to condense 300-odd pages of a book into 2-5 pages, but I'm here to help you out! This service includes an initial critique of your synopsis and help with up to two revisions thereafter to get it right.


Submission Critique Package - Query + First 50 pages - $250

​If you're getting ready to submit your manuscript to agents or publishers and are just looking for some help polishing those opening pages and your query letter, this service might be for you. It includes line edits done with track changes in Microsoft Word, as well as an edit letter detailing the strengths and weaknesses of your opening in terms of plot, characters, setting, and conflict.


Full Manuscript Critique - Developmental Editing (Starting at 1.3 cents per word)

This package is intended for writers who need help with pacing, characters, world-building, style/voice, and other areas of polishing craft in their manuscripts. I will leave comments within the document with questions/suggestions for improvement as I read, and also provide a summary of the strengths and weaknesses of your manuscript, offering suggestions to help you make it the very best book it can be.


Full Manuscript Editing - Line Editing/Copyediting (starting at 1.6 cents per word)

​This service includes line edits done with track changes in Microsoft Word, focusing on sentence-level issues such as grammar, spelling, punctuation, dialogue, and voice. This package is best for manuscripts that have a strong foundation but need stylistic work, though I can also include comments on pacing, plot, characters, and conflict if you request it.

Ready to get started? The first step is to email me at stephaniediazbooks@gmail.com and tell me about your novel to receive a personalized quote. Please include word count, genre, and a short pitch. I look forward to chatting with you!