Hi. Another noob here. Trying to learn all I can and get feedback. I also need to learn more about critiquing other author's work so I'll be doing a bit of lurking at first. Nothing creepy.
Welcome to the pit. Just remember there is no truely wrong way to do anything. That doesn't mean people won't take it the wrong way. I say jump in and let trial by fire set your path.
What I would say it's mostly free, except obviously (and this really should go without saying, but I've had some weeeiiird critiques in my day) demonstrate you actually read the work. Don't post a review of Die Hard on a Beauty And The Beast critique thread.
Or if someone posts a new draft, well who would have thought, that new draft is there for a reason. I've had to switch completely to only posting queries just to test writing board qualifications. We live in a day where everyone thinks they can be a critic.
When critiquing, I don't think it ever hurts to simply say what you're thinking/feeling. I'm confused, I'm bored, I'm thrilled, I'm mad at this guy, I love this gal, I think this guy's stupid, I think what he did was stupid, I don't understand why she's saying this, this dialogue feels fake, this dialogue is riveting, holy shit I didn't see that coming, this was super predictable, that was a funny line, etc...
That I can agree with.
The most important thing about critiques is honesty. That and the "why" of everything - as in don't just tell me something doesn't work, tell me why it doesn't work. Offer suggestions on how it could be fixed. But seriously don't worry about it, the more you do the better you'll get, and also the better you'll get at self critiques too. When you post your own stories and get critiques back you'll pick up tips and techniques from them too. Basically it all good.... except those odd critiques that aren't and well... just go with your gut there :)
Oh, and welcome to LitReactor, enjoy your stay :)