When I say beware of bad editorial advice on the web I'm not talking about all advice. There are more than a few places where writers can go to get excellent advice. There are also excellent editing/writing web sites where writers can go to get varying opinions. And that's what you want: varying opinions so you can decide what's right for you.
What I'm talking about when I say beware of bad editorial advice usually pertains to loud unpublished amateurs who think they know it all. And they don't. They will trick you into thinking they know it all. But I've never seen one who got it right. In some cases they remind me of used car salesmen from the old days.
They set bad detailed rules about what's considered good editing/writing and what's considered wrong editing/writing. They never list publishing credits, they never talk about their own publishing experiences, and yet they lead you to believe they know more than anyone else in publishing.
Here's an example of the difference between good and bad advice. There's been an age old debate about whether or not prologues work...or for that matter whether or not they should even be written. The best advice would be there's no set answer to this. Prologues work well for some books and some authors, they don't for others. Most readers don't seem to care one way or the other. Now, bad advice about prologues is when you see someone slam them and tell you never to do them. Frankly, I'm not a prologue fan and I hardly ever write them. But I've read books with prologues that worked and I would never tell anyone not to write a prologue. I might tell them to be cautious about prologues because I don't like them. But I'd never say never.
Another age old debate has to do with showing verses telling. A literary agent recently posted some great examples of how "telling" can actually work out well sometimes. I not only agree with her, I trust her advice because she has good credits that back her up, and authors who have been on all the bestseller lists. In other words, she knows what she's doing, at least in this respect. And in her post she gave good solid examples of how "telling" works sometimes. Once again, bad advice is when someone without any publishing credentials states "telling" is always bad and you should never, ever do it.
I always find it interesting when beta reader advice is given to writers. I've been working in publishing and getting published for twenty years and I've never had a beta reader. My publishers are my beta readers. The editors and copy editors who work for my publishers are my beta readers. The two times I've self-published the copy editors I've hired are my beta readers. But when I'm writing I work alone and I don't want anyone else's influence in my work. And yet once again, this works for me and I would never tell anyone else they shouldn't have a beta reader. It's all about what works for you and what makes you comfortable. I'd rather eat dirt that have a beta reader. I know other authors who depend on their beta readers and crit groups. And there's nothing wrong with either way.
Aside from all this, I think the biggest piece of bad advice I've seen of all time from amateur unpublished editors on the web is that you need to have a fully professionally edited manuscript before you submit it to a publisher or an agent. I've never found this to be true. You do need a neat, clean manuscript that's grammatically correct and easy to read. You do need a good story and a great hook if you're unpublished and you're trying to get an agent or an editor to notice you. You need to know how to write a great query letter with a perfect book/plot description to get the agent or editor's attention. And you need to know the basics of crafting a novel. But you don't need to pay a high priced freelance editor out of pocket if you're in the query stages.
This is what publishers do if they decide to buy your book. They edit the book, not you or the freelance editor you hired before you started to query. Some agents even edit before they start shopping books to publishers. I've seen this more often than not. But you don't need to spend hundreds of dollars on a freelance editor if you're querying and shopping a book. For some, this is where beta readers can come in handy. They can help you get the manuscript to the point of being neat, tight and ready to submit.
Over the years I've worked with more editors and publishers than I can count offhand. The editors I've least enjoyed working with have teaching experience, especially on a college level. In fact, I usually don't submit to them more than once because it's too frustrating to deal with them. They. Know. It. All.
But each time I've submitted a book or story to a publisher the editing process was a different experience. For one recent book that I released with a pen name, I submitted the book thinking there were very few things that needed to be changed. That's usually how it works out. However, the editor returned the manuscript and asked me to cut 8,000 words and turn the first chapter into the prologue. And guess what? That editor was right. I did what she asked me to do and it made the book better. And I'm the one who hates prologues. Go figure. As a sidenote, I also turned the 8,000 words I'd cut into a short story and sold it to another publisher. Like a chef who doesn't believe in wasting food, I don't believe in wasting words.
Before I submit a manuscript I do all kinds of checks. One of those checks is to look for words I sometimes write too often without realizing it. One of those words is "that." I do a search, find, and delete. My copy editor usually thanks me for this. But it doesn't always work out this way. I once submitted a manuscript to a publisher and the managing editor sent it back with revisions. And huzzah, she'd added the word "that" in all the places where I'd removed it. But better than this, when it came back for the final read through from the copy editor, she'd removed the word "that" in each place where the managing editor had inserted it.
I've always found that my copy editors are the most important people with regard to getting a book out. I depend on them more than anyone in publishing, because they are the people that can make or break a book. I've worked with many and they all have different styles and different opinions, too. The best know the meaning of the word diplomacy. Which leads me back to where I began in this post: there are not set rules and anyone who tries to tell you there are isn't someone you want to take seriously. So beware of that kind of advice. It's only going to leave you wondering why you bothered to listen in the first place after you've had a book published and found out what it was really like to go through the editorial process. Believe me, it's nothing like what they say. And that's because it's always different, with each book, each professional editor, and each publisher.