The thing that I most think of when I hear the words "constructive criticism" are my old days of reviewing fanfiction - and sometimes my new days of reading and writing in the erotic romance community, and teaching creative writing - and how there are quite a few people out there who really seem to struggle with what the term really means. So here I am, with my half-baked opinion on that very thing! It's like a lesson, only rubbish and probably too much about cocks.
Anyhoo, basically, if you've written a terrible mess of a story (which at some point in every single writer's life will definitely one hundred percent happen. Unless you're, like, the Mozart of writing. But if so, prepare to be killed by F. Murray Abraham), what you're unlikely to hear if someone is really constructively criticising are any of the following sentences:
1. You're amazing!
2. There are just a few typos to fix but otherwise brilliant!
2. I'm not sure what the other constructive criticisers were going on about, because you've written golden perfection on top of magnificent genius. Also, they are meanies.
In fact, even if you haven't written a disaster, you probably won't just hear variations on those sentences. If you do, someone's pulling your plonker.
Similarly, however, you shouldn't be hearing things like this if someone is truly constructively criticising:
1. You suck. Go die in a fire.
2. Never write again.
3. Eat a bag of cocks.
I mean, even if I'm wrong about this whole defining constructive criticism thing, that third one is definitely right out. Unless your "crit" "partner" is also one fifth of the five-way polyamorous relationship you've got going on. Then maybe they're just talking about that bag they bought, with the four holes cut in it.
But I digress, about cocks, as usual.
What I really wanted to say was- constructive criticism is and always has been the fine art of nailing the issues in your work, giving you a way of working on them, and doing both without getting personal. It can be harsh. It can be brutal. It can be as much as this:
"Pages and pages of inner monologue on one tiny detail is too much. You're dragging your narrative down, and boring the reader to death. Tighten focus, or lose your reader forever."*
But that does not make the constructive criticiser a huge awful meanie. It makes them a good person, who isn't willing to let you go out into the world half-naked, because that morning you forgot to put your trousers on. In this context, "you are awesome" is just as bad and damaging as "eat a bag of cocks". One of them just makes you feel bad and look like a fool later on, and by tiny, stabbing increments. Courtesy of much, much more important people.
Because that's what you're aiming for, right? The much, much more important people? The editors and agents and the people who will publish your work? And good constructive criticism will prepare you for that world, in more ways than one. It not only helps you not look like a fool, it also shows you what a relationship with a good editor will look like.
A good editor will not sugarcoat it. They won't cheerlead and squee and come in their pants when you've used the wrong affect/effect and your heroine's motivations are deeply unclear. They'll tell you straight, and expect you to work with them on these things, and they won't take kindly to you telling them they're stupid and a bitch and that they should go die in a fire.
Learning to differentiate between meanness and constructive criticism is a vital weapon in a writer's armory. Find it now, learn it now, and it will serve you forever.
*Yep, that was a piece of crit aimed at my work. I've had harsher, but that one stands out as the most helpful, as well as being pretty tough- the hallmark of good CC.