Properly applied, critique is about getting better, not getting judged. You can use critique at any phase of your writing, from casually floating concepts to hard, valuable, nitpicking at (what you'd wanted to be) your final project.
Big problem: you're a writer, not a sculptor. A sculptor can ask a critic over and over "does that nose/chin/fetlock look right now?" A writer can only so many times say "does my book/column/article read better now?"
So, using your critic(s) with due discretion, ask what they can do for you. To which the short answer is that they see the wood that for you has become obscured by the trees, in seven ways.
Never underrate the capacity of a critic's casual word or phrase to nail down what you are trying to say. You can spend hours chasing your fleeting conceptualisation, you can think it through and through and through, and not find the nub ... until another pair of eyes goes through it and the mouth attached to them innocently pipes up "Oh, are you trying to say X...?"
Every writer knows that a great introduction is crucial to ensnaring the time-deprived reader. But writing introduction after introduction lessens your enthusiasm for the perfect start. Your bag of tricks runs dry and resembles an empty wine skin, you feel you get stuck in a rut. Your critic can provide new ideas that had escaped you. Your imagination engaged; your readers are enthralled.
Okay, you've got your pyramids down. But sometimes it's not so clear what is on a 'higher' or 'lower' level. Some points are just on the same level, or are they? Hear that outside perspective on whether your pyramid is looking more like a rhomboid or dodecahedron; whether your piece flows, floods or splats.
Your conceptualisation, introduction and structure may be good, but you are working from yesterday's news, you simply did not hear the latest. You remember learning in school that dinosaurs are ancient reptiles, and trusting your favourite teacher, you insert this confidently as fact. Or you missed the latest in the on-going saga of Nkandla, and your reader dismisses your point for that gap. Science and news have moved on and you're chasing, rather than being on top of them. Someone who has heard the latest will notice and fill that gap.
I'm not necessarily talking about typos and grammar here, but the things that any one single brain can glide over where a second and separate brain will erect a question mark. That can range from historical "fact" to where urban legend has become orthodoxy to the simple places where the over-familiarity of an authorial eye glides over the "rein in" showing up as "reign in".
Having studied your formal and informal logic, you know your reductio ad absurdum from your argumentum e silentio. Not?!? But even Wittgenstein took help detecting fallacious logical leaps in his work. To get it right every time takes more than a genius; it takes a computer. And when you are dealing with a topic close to your heart, the reasoning in your head may look very flat to a detached pair of eyes. Solution: a reliable pair of detached eyes before your work goes public.
"Length" in writing is less about wordcount than about verbosity. It is the economy of your writing. No word limit can stop you from introducing more points than you can explore, or torturing your reader with what you think is an intriguing tangent or a slice of wit, but they see as obfuscation. Here you must force your critic to suppress the urge to be nice and embrace the duty to be honest, (as well as the humility to accept that the critic is testifying; it's the author who judges).
Goodbyes can be hard. This is true in writing as in life. An attempted summing-up can become dreary reiteration. Many written works trail away vacuously like lowering the sound on a musical recording. Rare is the art of stopping so the reader gets the whole and hums the tune of your thoughts through their day. When you are relieved to have dashed off the final word, the critic may detect your flagging energy, and suggest a better stopping point or spark an option that your overwrought eyes could not see.
