I have been a member of Critters for some years (3 or 4, I think) although I took last year off due to other commitments. I have found the community to be very welcoming and helpful and I would recommend it to anyone serious about improving their writing. There are one or two hints that might help you get the best from the site that I thought I might pass on for those unfamiliar with the way it works.
You can submit pieces up to 20,000 words for the queue, but bear in mind that work over about 5,000 words may receive fewer critiques simply because of the time it takes to prepare a longer critique. Between 3,000 and 6,000 is about the optimum in my experience.
If possible do not use MS Word to format your text as it inserts strange characters that do not display well. Critters works best with plain text (chosen because it is macro and virus free) but that means that you have to highlight *bold* and _italic_. If you do use Word, make sure that 'curly quotes' are turned off.
Critique for pieces under 2,000 words only gets you half a credit, but it's useful to have one on these credited as sometimes you don't get time in your week for a full critique and you can submit a short work critique and use the other half credit to earn your credit for that week.
It really helps to get into the habit of critiquing regularly, so I recommend you choose a day that's normally best for you and do it then as part of your weekly routine. I used to commute and do my critiques on the train, but whatever works for you.
It helps to use the critters mechanism to develop your 'editing mode'. In time you will come to see this as part of your writing, not a distraction from it. You will likely find yourself being harder on your own work as a result.
You will occasionally get damning critique through Critters. It happens. The truth is that there is always someone that does not appreciate the way you write - your style, voice, whatever. It helps that critters will provide you with a number of critiques, so that you can balance the negative remarks against the positive. If you're going to be a writer, though, you have to get used to negative reviews. Take what you can from it and move on.
If you are new to Critters or less confident about your work, then say so. There is an opportunity at the beginning and the end of your submission to add author's remarks, so use this to say "Hey, this is my first time - be gentle" or similar. The rest of them have all been there, they will understand.
You needn't just use Critters to critique your writing, it can also be useful for getting comments on agent query letters, a synopsis, magazine articles or other writing-related pieces. They do need to be within Horror, Fantasy and SF genres, though, and short pieces still only earn a half credit.
If you are using profanity and/or your material contains adult themes or explicit material then you should also say so in the remarks before the piece. This helps to limit some of the adverse comments.
Bear in mind that some of the Critters are juniors (under 13) so some of the pieces (and some of the critiques) may come across as naive or lacking life-experience. They probably won't tell you that they are juniors, so bear it in mind when phrasing your comments.
Finally, it is a generally accepted politeness to email back a thank you note when you receive your critique, even if it is just "Thank you for your remarks, I will bear them in mind when I re-write." If you have found someone's remarks to be really helpful then say so. You could make someone's day.
Hope that helps to improve your experience of Critters. I have certainly found it useful and recommend it to others.
