Siân Heap

Siân Heap – Editor

Commercially-minded & supportive editor with experience publishing bestsellers. I work with everyone from Big 5 publishers to debut authors

Overview

Working with authors to bring their books to life has always been my favourite part of the job – I’m thrilled I get to spend every day doing it.

My editorial style is backed by 7 years of publishing experience. I specialise in genre fiction and I want to help you create a page-turning bestseller. I’ll show you what is working and explain why things aren't so that we can take your writing to the next level.

Before going freelance, I was a senior commissioning editor for leading independent publishers, specialising in crime and thriller. As a freelance editor, my publishing clients include Harper Collins, Embla, Hodder & Stoughton, Canelo and Joffe Books.

I specialise in developmental editing and use my years of publishing digital and print bestsellers to help you realise your vision. Authors I have worked with have gone on to become Amazon bestsellers, been shortlisted for major prizes and had their lives transformed by their writing careers.

I’ll show you what is working and explain why things aren't to take your writing to the next level. I know writing can be an emotional process and whatever path you want your publishing journey to take, I’m here to guide you through the editing process with sensitivity and care.

I believe writing is a human process – I do not use AI and would prefer not to work on books that have been written using the assistance of Generative AI.

Services
Fiction
LGBTQ Fiction Mystery & Crime Romance Thriller & Suspense
Languages
English (UK) English (US)
Certifications
  • University of St Andrews - Modern History & English Literature, MA (Hons)
  • Oxford Brookes University - Publishing Media, MA
  • Copyediting 1 – The Chartered Institute of Editing and Proofreading

Work experience

Self-employed

Apr, 2025 — Present
I’m a freelance editor and publishing consultant working with authors and publishers. I specialise in commercial fiction and have extensive experience editing and publishing bestsellers.

Joffe Books

Jul, 2024 — Apr, 2025 (9 months)
- Commissioning crime, thriller and suspense resulting in multiple Kindle Top 100 Bestsellers directly from authors and from established literary agents - Guiding authors and agents through the publication process from acquisition to publication day and beyond - Providing detailed structural notes and feedback on manuscripts - Utilising market knowledge to acquire, brief covers and write engaging blurbs for a commercial digital readership

Canelo

Apr, 2019 — Jul, 2024 (over 5 years)
- Commissioned and published both established and debut authors in the commercial fiction, specialising in the crime and thriller genres - Structurally edited titles, wrote copy, briefed covers, read direct and agented submissions, optimised book metadata and created publication strategies - Worked closely with authors and agents, both domestically and internationally

Portfolio

Developmental Editing
Developmental Editing
Developmental Editing
Developmental Editing Copy Editing
Copy Editing
Nothing Left Behind (Detective Liz Field, Book 2)

Hannah Brennan

HarperCollins Publishers

‘Emergency. Which service do you require?’ ‘He’s trying to burn down my house. He’s going to kill me.’ They thought it was another false alarm. They were wrong. This page-turning crime thrille... read more
Copy Editing
Copy Editing Editorial Assessment
The Husband: An absolutely gripping psychological thriller (Unputdownable Domestic Suspense)

O'SULLIVAN, DARREN

Joffe Books psychological thrillers, suspense and crime

Developmental Editing
Developmental Editing
Developmental Editing
Developmental Editing

Siân has 5 reviews

Professionalism

Quality

Value

Responsiveness

Clarisse H.

Clarisse H.

Dec, 2025

Pinned
Siân copyedited my manuscript using CMOS and provided additional line/developmental notes as necessary. She was incredibly helpful, kind, and professional throughout the process. Her excitement about my initial draft made me excited to work with her! Siân's suggestions and comments pointed out t...
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Siân H.
Thank you so much Clarisse. I loved working with you and I'm so excited to do so again!
Patricia R.

Patricia R.

Jun, 2025

Pinned
Siân did a developmental edit of my novel. Her work was very thorough. She prepared an editorial report and also added multiple comments in the manuscript. I'm really happy I chose her. Her thoughts and suggestions were incredibly insightful and inspiring. They made me think of aspects I hadn't ...
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Siân H.
Thank you so much Patricia! It was such a pleasure to work with you and on your brilliant novel. I'm looking forward to working together again!
Shelagh H.

Shelagh H.

Jun, 2025

Pinned
Siân provided an impressive manuscript assessment. She identified elements that, in her view, needed attention and she was correct and helpful at every turn. She saw the big picture of the story and provided encouraging and realistic feedback. I don’t hesitate to recommend her to anyone thinking ...
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Siân H.
Thank you so much Shelagh! I'm so pleased you were happy with the edit – it was such a pleasure working with you. Good luck with the next steps!
Clarisse H.

Clarisse H.

Feb, 2026

This is my second time working with Siân. She provided copyediting according to CMOS and developmental notes as needed, along with an additional editorial letter outlining her high-level thoughts. Siân was once again a phenomenal editor. Her comments really help elevate my story, making it stron...
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Patricia R.

Patricia R.

Sep, 2025

Siân did a review of my agent query package and provided excellent suggestions. It's looking all the better for it. She had previously done the developmental edit of the novel which was incredibly helpful. She is very reliable and always delivers the work on time. She responds promptly to any que...
Read more
Siân H.
Thank you so much, Patricia! It was such a pleasure to work with you. Wishing you the very best in your querying journey – I'm keeping all my fingers crossed for you!

Most recent contributions

How do you balance being critical while encouraging authors through your feedback?

I always want to give actionable and clear feedback to an author. Although pointing out weaknesses in a manuscript can feel like criticism, it’s never meant as such. It’s my job to provide insight for why something isn’t working so I always endeavour to find a balance between explanation and su...
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What's the best piece of writing advice for an author who wants to improve their craft?

Practice and read! In the same way that you need to practice a musical instrument to get better, you need to do the same with writing too. Very few writers will publish the first book they ever write! The other thing that will help you to improve your writing craft is reading. Read the books t...
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How do editors stay updated on current trends in publishing?

As a commercial fiction editor, I need to make sure I'm keeping up to date on the latest trends in publishing to ensure that I'm advising my clients appropriately. I do this through being a member of professional organisations like the Charted Institute of Editing and Proofreading and taking prof...
Read more

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