Ordering the wrong level of work
The four common services do different jobs, and the professional bodies describe them in terms specific enough to compare. The Editorial Freelancers Association places developmental editors on content, organization, and genre considerations. Line editors work at the sentence or paragraph level, correcting errors while concentrating on the language and style of the text. Copyediting covers spelling, grammar, usage, and punctuation, along with checking cross-references and preparing the style sheets that hold a manuscript consistent. Proofreading comes among the last stages of preparing a manuscript for publication, and proofreaders check for typographical errors and formatting mistakes.1
Reading those four in order shows why the wrong choice is expensive rather than merely disappointing. A proofread of a manuscript with an organizational problem returns a correctly spelled manuscript with the same organizational problem. Editors Canada draws the line in one sentence, recording that proofreading is not a substitute for editing.2
The reverse mistake costs money instead of time. A developmental edit commissioned for a manuscript whose argument is already settled pays sentence-level rates for a report the author could have written.
Editing a draft that is not finished
The EFA's guide for new authors advises completing or substantially shaping a manuscript before looking for professional editing, and suggests a writers' group for feedback beforehand.3 The advice is practical rather than territorial. Chapters written after an edit has begun arrive in a different style from the chapters that were edited, and the difference is visible.
There is a pricing consequence as well. A quotation produced from a ten-page sample is an extrapolation, and later chapters written under different conditions can be denser than the opening. A figure produced after reading the whole manuscript can be held to. The same guide records that rush work commands higher rates, which makes a late-arriving chapter more expensive than an early one in two separate ways.3
Leaving the style decisions unrecorded
Copyediting includes preparing the style sheets that guide consistency and accuracy across a manuscript.1 Editors Canada includes the development of style sheets within its own definition of copy editing, alongside checking mechanical consistency.2
A style sheet is a written record of the decisions a manuscript has already made. It sets down which spelling convention the book follows, how numbers are treated, whether a character's nickname takes an apostrophe, and how a recurring term is capitalized. Where no such record exists, the same question gets answered differently in chapter two and chapter nineteen, and a later reader has no way to tell which answer was intended. Authors who ask for the style sheet at the end of a copyedit generally find it the most useful document they receive, because it is the one that makes the next book cheaper.
Skipping the permission that graduate work requires
Academic writing carries a constraint that trade publishing does not. Editors Canada states that all graduate student and doctoral candidate clients must obtain written permission for professional editing from their advisor, whom the guidelines call the supervisor. The permission has to specify what the editor is allowed to do, and the editor, the advisor, and the student must all understand the limits of the edits permitted.4
In the absence of specified limits, the same guidelines say editors should not go beyond simple correction of grammar, idiom, punctuation, spelling, and mechanics, retaining content and overall structure.4 A student who commissions a line edit without that conversation may receive work their institution does not permit them to submit, and the discovery usually comes too late to undo.
Agreeing a price without agreeing a scope
Writer Beware, the industry watchdog run by the Science Fiction and Fantasy Writers Association, names the warning signs directly. An editor who will not give a firm price, will not specify what the fees cover, or will not say who will be working on the manuscript is one to move on from. A demand for full payment upfront is a warning sign, as are unsolicited editing offers. A reputable editor should have no difficulty providing a resume, references, and a disclosure of fees.5
The EFA's guide adds the check that costs nothing: asking what other work an editor has done on similar books, and asking for references from previous clients.3 It also notes the limit of a sample edit, which can help in evaluating copyediting or line editing but cannot capture developmental work, since the scope is too large to show in a few pages.3
Everything a client sends is treated in confidence, including unpublished drafts, research data, and correspondence. EditFast quotes on the whole document, states which level of work the figure covers, and works to the client's chosen style authority rather than imposing one. Deciding the substance of a client's field, or the merits of their argument, is not an editor's business.
Authors who make all five of these mistakes on a first book usually make none of them on a second. That is an expensive way to learn something both professional associations have already published.